—to Ibn Ḥibbān and to al-Ḥākim in his al-Mustadrak as well. In another place of al-Kabīr (1/21/1) he further attributes it to Ibn al-Sunnī in ʿAmal al-Yawm wa-l-Laylah and to al-Ṭabarānī in al-Kabīr. I have not found it in the Mustadrak after checking the chapters on Righteousness, Maintaining Ties, and Etiquette; Allah knows best.

Among the supporting reports is what Aḥmad (3/438) recorded through Ibn Luhayʿah—Zabān narrated to us from Sahl ibn Muʿādh, from his father, that the Messenger of Allah ﷺ said:
“It is a duty upon whoever approaches a gathering to greet the people there with salām, and it is a duty upon whoever rises from a gathering to greet them with salām.”
A man then stood up while the Messenger of Allah ﷺ was speaking and did not offer salām, so the Messenger of Allah ﷺ said, “How quickly he forgot!”

I say: This isnād is weak, yet it is acceptable for corroboration. It is further strengthened by al-Bukhārī’s presentation of the report in al-Adab al-Mufrad (1009) through another chain, from Basṭām, who said: I heard Muʿāwiyah ibn Qurrah relate that his father said to him:
“My son, if you are in a gathering from which you hope for benefit and some need compels you to leave, then say, ‘Salām ʿalaykum,’ for by doing so you will share with them in whatever good they obtain in that gathering. Any people who sit together and then disperse without mentioning Allah are as though they departed from the carcass of a donkey.”

Its chain is sound; all its narrators are trustworthy. Although mawqūf, it carries the weight of a marfūʿ report, for such a statement is not said on the basis of personal opinion—especially considering that most of its content is authentically transmitted as marfūʿ. The first portion appears in the present ḥadith of Abū Hurayrah, and the latter portion is also narrated from him; see ḥadith no. 77, together with what precedes and follows it.

Offering salām when rising from a gathering is an etiquette that has fallen into neglect in some lands. Those with the greatest claim to revive it are the scholars and their students. Thus, when they enter upon the students in a classroom, for instance, they should give salām, and likewise when they depart, for the first instance is no more deserving than the second. This comes under the general instruction to spread salām, as will be mentioned in the following ḥadith:
“Salām is one of the names of Allah which He has placed upon the earth, so spread salām among yourselves.”