[Commentary]
Imam al-Nawawī, may Allah have mercy on him, states: “Chapter: Bidding Farewell to a Companion, advising him when parting for travel or any other separation, praying for him, and asking him to pray in return.”
When someone sets out on a journey, his family, relatives, and friends ought to bid him farewell and exhort him to fear Allah, for Allah the Exalted says, “We have already enjoined upon those who were given the Scripture before you, and upon you as well, that you should remain mindful of Allah.” Whenever the Prophet ﷺ dispatched an army or a detachment and appointed a commander over them, he would say to him, “I counsel you to fear Allah and to treat the Muslims who are with you well.”
A person needs others to help and encourage him to obey his Lord—especially while traveling, because travel is a time of preoccupation and inevitable shortcoming, all the more so in earlier times when journeys were long, made on riding animals or even on foot. For that reason people were in need of advice, reassurance, and assistance.
The author, may Allah have mercy on him, then cites the pertinent Qur’anic verses, among them Allah’s words: “And Abraham enjoined this upon his sons, and so did Jacob, ‘My sons, Allah has chosen the religion for you; so do not die except in a state of submission.’” This counsel is none other than the word of Allah Almighty.