Historical Dimension
There are many threads to the historical aspect of this Bani. The first of these is related to the revelation of the Sabads in this Bani. We can take the Sabad of 'Arti' as an example.

Its second thread is connected to the time of recitation of this Bani. For example, both Faridkoti and Sampradai tikas (denominational commentaries) had initially indicated this Bani to have been read in the afternoon. According to them, at the request of Bhai Lahina (later Guru Angad Sahib), Guru Nanak Sahib ordered the recitation of this Bani at night before going to bed. After that, it became customary to recite this Bani at night.
Adi Sri Guru Granth Sahib Ji Satik (Faridkot Wala Tika), volume 1, page 36; Kirpal Singh (editor), Sampradai Tika Sri Amir Bhandar Sri Guru Granth Sahib Ji, volume one, page 220-221.

Bhai Santokh Singh has described this incident as follows: One day, the light of the Bedi clan (Guru Nanak Sahib) was sitting. (Bhai Lahina) sitting close was massaging the Guru’s feet. When he noticed the Guru’s calves, they were severely bruised. Bhai Lahina clasped both hands and asked, ‘O bestower of freedom (Guru Nanak Sahib)! How did these thorns get pierced (into your calves)? You never went to such (thorny) places. These bruises seem to have occurred recently. Tell me the reason.’

After listening to Bhai Lahina’s words, the Guru replied, ‘A shepherd is grazing the flock (sheep) in a place with many thorns. He is roaming around and reciting Kirtan-Sohila with a focused mind, full of love. I am walking with him. I cannot let his limbs get pricked by thorns. Understand that I have received these bruises from there. O Lahina! Accept my words as the truth. Wherever anyone recites Kirtan-Sohila, I am with them.’

After saying this, the Guru called a Sikh and (Guru Nanak Sahib) the bestower of freedom said, 'At a certain place, the shepherd is grazing the flock with great love. You look for him and bring him here with the utmost respect.'

On hearing the Guru’s words, the shepherd accompanied the Sikh and came to the Guru and bowed at his feet. The Guru looked at the shepherd with grace and said, ‘Read the Bani of Kirtan Sohila, that you remember, at night before going to bed. Doing so will bring happiness, and jealousy will vanish from the mind.' On hearing this, the shepherd said, ‘As you wish, now, I will recite [the Bani] with love in my heart at night, and I will understand this to be the peace-giving deed.’
Adapted from Kavi Churamani Bhai Santokh Singh, Sri Guru Nanak Prakash, Utraradh (volume two), Dr. Kirpal Singh (editor), page 498-499.

According to the Faridkoti Tika, only the first three Sabads were recited in this Bani till Guru Arjan Sahib’s times. The Guru expanded this Bani by adding the last two Sabads to it: “This tradition of Sohila started with the first Guru, the recitation of three Sabads continued. At one point, a merchant Sikh begged in front of the fifth Guru, O true King! We people have to live in horrible places abroad because of thieves or ghosts. So, please give us a mantra (incantation) through which we can be protected. Then the Guru combined the first three Sabads with two more Sabads and said Sohila Mantra, one Sabad of the fourth Guru, and one of his own. This Sohila Mantra is the guard, just like the lock on a strong fortress, it is the guardian of the wealth of Sikhs; ‘Japu’ Ji is its key.”
Adi Sri Guru Granth Sahib Ji Satik (Faridkot Wala Tika), volume 1, page 36-37.

Just as the historical aspect of this Bani is revealed from the above narratives, it is also clear from them that the Guru is always with the Sikh. Especially when the Sikh connects with Bani. Therefore, a Sikh needs to have complete faith in the Guru's Bani instead of wandering elsewhere.

Sabad 3
The utterance of this Sabad is related to the Jagan Nath temple in Puri (Odisha).
The descriptions of this province, situated on the eastern shore of India, has appeared with different names in the old literature. Out of these names, Audar, Paundar, Kaling, Utkal, etc. are available in Mahabharat. Ashoka Maurya conquered this province in 261 CE. -Vijendar Kumar Mathur, Itihasik Sthanavali, page 148.
Guru Nanak Sahib reached the Jagan Nath
In different regions of Hindustan (including Bengal), a particular idol of Vishnu or Krishan called Jagan Nath is worshipped. It has a huge following in Puri (Odisha). People from all over the world gather for the rath-yatra festival (in which the idol of Jagan Nath is brought out on a chariot), celebrated during June-July (Har Sudi 2nd). On this occasion, the idol of Jagan Nath is placed on a forty-eight foot high chariot made of sixteen wheels. This chariot is accompanied by two more chariots, one of Balram and another of Bhadra. The chariot of Balram is forty-four feet high with fourteen wheels, while the chariot of Bhadra is forty-three feet high with twelve wheels. In the ancient times, people used to give away their lives by throwing themselves under the wheels of these chariots in order to attain liberation. ...there is an interesting story in the Sakand Puran (a collection of myths and legends of Sanatan tradition) regarding Jagan Nath, [which says that] when the hunter ‘Jar’ killed Krishan, his body decayed lying under a tree. After some time, a devotee secured his bones in a box. Vishnu (one of the three principal deities in Hinduism, who preserves the creation) ordered the king of Odisha, Indradyuman, to make an idol of Jagan Nath and place Krishan’s remains within that idol. On the request of Indradyuman, Vishwakarma, the mason among the deities, started making the idol on the condition that if someone saw the idol before it was completed, he would stop working on it. Within a fortnight, the king lost patience and went to see Vishwakarma. Vishwakarma, in anger, stopped working on the idol. Consequently, the idol was left incomplete without hands or feet. Accepting the request of King Indradyuman to complete the idol, Brahma (one of the three principal deities in Hinduism, who has created the creation) gave eyes and life to the idol, and installed it with his own hands but historical facts prove that Jagan Nath temple was made by King Anant Verma, who ruled the region between the river Ganga and the river Godavari from 1076 through 1147. -Adapted from Bhai Kahn Singh Nabha, Mahan Kosh, page 500.
temple while traveling from Bengal. “He passed through Mayurbhanj and Balasore districts of Orissa crossing Vaitarni, Brahmani, and Mahanadi rivers… The Guru rested on the banks of the Mahanadi river at Cuttack and visited the ancient temple of Dhavleshwar Mahadeva... After this the Guru headed towards Bhubaneswar.”
Now a Gurdwara stands at the place where the Guru took rest which is known as Gurdwara Guru Nanak Datan Sahib or Gurdwara Kaliaboda. It is believed that while brushing his teeth with a twig (datun) from the Sahra tree, the Guru planted a little twig of the Sahra tree at the site which grew into a big tree with time. This old tree fell some time ago, and a log from its trunk is preserved in the Gurdwara. From the roots of the old tree, another tree has grown up. When the author visited this tree in June 1969, he noticed a small inscription on a wooden slate around the tree which bears the Mul Mantra (opening verse of the Guru Granth Sahib), the name of Guru Nanak Sahib and the word Vahiguru (a synonym for the Divine in Sikh parlance). Close to this inscription, there is a small Sivalingam (a symbolic representation of the Hindu deity Shiva) and a small statue of Nandi Bull of Shiva that indicated the claim of the Shavites of Cuttack, to this place. The priest of Dhavaleshwar Mahadeva temple was highly inspired by the Guru’s thoughts and he expressed his wish to be a disciple of the Guru. The ruler of this place also came to see the Guru and donated the piece of land to him. A part of this land is under the possession of the management of the Gurdwara and partly under the possession of the Udasis. It is said that an Udasi from Panjab settled here. He advised the local people to remember ‘Vahiguru.’ For this reason, the Gurdwara also came to be known as ‘Vahiguru Math.’ -Adapted from Surinder Singh Kohli, Travels of Guru Nanak, page 58-59.

During the times of the Guru, a king named Paratapurdev,
Meharban has recorded his name as Bharthari. -Kirpal Singh, Shamsher Singh Ashok (editor), Janamsakhi Sri Guru Nanak Dev Ji, page 200.
a follower of the Vaishnavite sect, ruled Odisha. The Guru met the famous Vaishnav Bhagat, Chaitanya also, here. According to the Puri Gazette, Chaitanya came to Odisha in 1510 CE.
L.S.S. O’ Malley, Bengal District Gazetteer, page 31.
Guru Nanak Sahib also arrived in Odisha around 7 June 1510 CE during the rath yatra festival.
A major Hindu festival, associated with Lord Jagannath (an incarnation of Lord Vishnu), is held at Puri in India during the month of June or July.
This is considered to be during the first journey the Guru took.

It was here that the Guru uttered this Sabad in Rag Dhanasari (a musical mode). By virtue of the Guru’s teachings, many hypocrites and transgressors like the main priest Kaliyug Pandit attained the status of Guru-centered (Gurmukhs). The place where the Guru stayed during this visit is known as ‘Mangumat.’ There is also a deep well (bauli) named after the Guru at this place. This place is looked after by the followers of Udasi
A Sikh denomination from the seventeenth-eighteenth century who preached as well as took care of the Sikh religious places.
Adapted from Bhai Kahn Singh Nabha, Mahan Kosh, page 500.

In contrast to this popular belief, Meharban Janamsakhi suggests that this Sabad was uttered in Rameshwaram.
Kirpal Singh, Shamsher Singh Ashok (editor), Janam Sakhi Sri Guru Nanak Dev Ji, page 211-212.
But Bhai Mani Singh Janamsakhi associates this episode with Jagan Nath. Dr. Kirpal Singh has also associated this episode with Jagan Nath by accepting the origin of the verbiage ‘malānlo’ (fragrance emanating from the sandalwood plants on fire at the Malaya mountain) and ‘anhatā sabad vājanat bherī’ (unstruck Sabad is resounding like a kettledrum) from the Oria language.
Dr. Kirpal Singh, Janam Sakhi Parampara: Itihasak Drishtikon Ton, page 71.

When the Pandit asked the Guru why he did not participate in the Arti being performed inside the temple, the Guru uttered the Sabad (Arti), which refers to the natural Arti continuously being performed in nature all the time. This has been described in the Janamsakhi of Bhai Mani Singh like this:

“tab mardāne nūṁ bāhar baiṭhāi kar bābā jī jagan nāth ke duāre par jāi baiṭhe. tāṁ pāṁḍe jagan nāth kī ārtī lage karan ate bābā jī samādh lāike baiṭh rahe. tab sabh pāṁḍe ārtī karke bābe pās āe baiṭhe ar unṁ kahiā, tusīṁjātrī āe ho. ar asāṁ mahārāj dī ārtī kītī hai ar tusīṁ kiuṁ nahīṁ kītī. tāṁ bābe kahiā, ki ek īsvar kī ārtī hai ar ek jīv kī ārtī hai. so hameshā ham suṇate haiṁ ar dekhade hai so aür ham kaisī ārtī karaiṁ. tāṁ pāṁḍe kahiā ki tusīṁ kaun sī ārtī suṇī hai. tāṁ babe sabad ākhiā: gagan mai thālu ravi candu dīpak bane tārikā manḍal janak motī… dhanāsarī mahalā 1. ārtī.9. -Guru Granth Sahib 663

“Then Baba Ji made Mardana sit outside and went to Jagan Nath temple and sat at its entrance. Then, the Pandits began performing the Arti of Jagan Nath, and Baba Ji remained sitting in meditation. After the Arti had finished, all the Pandits approached Baba Ji and asked him, ‘You are a pilgrim. We performed the Arti of the king; why didn’t you join us?’ Then Baba replied, ‘There is one Arti of the Supreme Being and there is another Arti of a [human] being. That Arti I hear and witness all the time, then which other Arti should I perform?’ Then the Pandit said, ‘Which Arti have you heard?’ Then Baba uttered the Sabad: gagan mai thālu ravi candu dīpak bane tārikā manḍal janak motī”… -dhanāsarī mahalā 1. ārtī.9. -Guru Granth Sahib 663

… tan eh bacan suṇke pāṁḍe carnā par gir paṛe. ate phir rāt ko jagan nāth supne maiṁ āiā ar tinoṁ pāṁḍiū ko kahā ki main hī nānak rūp dhāriā hai. jagat de udhār karan vāste. so tusīṁ prithme jis asthān te bābā jī baiṭhe han tis jagā dīvā ar pūjā karnī. bābā jī uthoṁ uṭh ke samundar ke kināre ā baiṭhe.
…then, hearing these words the Pandit fell at his feet. Later that night, Jagan Nath appeared in the dream and informed all the three Pandits that I myself have taken the form of Nanak, for the emancipation of the world. Therefore, first light a lamp and worship at the place where Baba Ji is sitting. Baba Ji moved from that place and sat near the sea shore.”
Dr. Kirpal Singh, Janam Sakhi Parampara: Itihasak Drishtikon Ton, page 380.

Here while addressing the head Pandit Kaliyug on their meeting, it is believed that the Guru uttered the Sabad ‘motī ta mandar ūsarahi ratanī ta hohi jaṛāu,’
Dr. Kirpal Singh, Janam Sakhi Parampara: Itihasak Drishtikon Ton, page 380.
depicting the worthlessness of worldly materials in comparison to the Creator’s Nam.
In the Guru Granth Sahib, the term Nam is vast. Thus the native term is retained for its literal representation. For its interpretive representation, the term “identification” is used as one active noun or verb form to represent our relationship with, connection to, and response to Nam at a human level. A description of the term Nam is as follows: Nam (noumenon, generally used in contrast to phenomenon) is a key term and the central principle in the Guru Granth Sahib. According to Professor Puran Singh, “Nam” is the supernaturally natural function of a poetical genius who though in body, is at all times of day and night under the influence of the higher Soul-worlds of Freedom...It is the pure subjectivity of love bursting up under the sole and invisible spiritual guidance from below the crusts of earthiness, from under the hard conditions of earthly life.” -Puran Singh, Spirit of The Sikh, Part II, volume two, page 36. Often, Nam is considered merely a word which is to be recited or repeated. Though literally a name or an identifier, Nam alludes to something much more vast, deep, and subtle than a mere name of the Supreme Being. Although numerous names or words for the Supreme Being (such as Ram, Hari, Gobind, etc.) are used in the Guru Granth Sahib, Nam also frequently appears instead of those names. Consequently, Nam also appears as a synonym for the Supreme Being among the many contexts in which it is invoked in the Guru Granth Sahib. Primarily, Nam is the central principle of Sikhi, around which the entire Sikh worldview revolves and evolves. When seen in the totality of the Guru Granth Sahib, in addition to being a synonym for the Supreme Being, Nam represents the active and creative facet of the Supreme Being, that is constantly creating, pervading, governing, and sustaining everything in the entire creation: nām ke dhāre sagle jant. nām ke dhāre khanḍ brahmanḍ. -Guru Granth Sahib 284 In Indic traditions (Buddhism and Hinduism) the term ‘nāma’ (name) is used to describe the spiritual or essential properties of an object or being, as opposed to ‘rūpa’ (form) that describes the physical presence that it manifests. In this way, Nam is also the Law or the Principle that governs the entire phenomenal world, and is the sum total of all the qualities and attributes of the Supreme Being.