(62) باب الْهِجْرَةِ
Narrated Abu Aiyub Al-Ansari:
Allah's Messenger (ﷺ) said, "It is not lawful for a man to desert his brother Muslim for more than three nights. (It is unlawful for them that) when they meet, one of them turns his face away from the other, and the other turns his face from the former, and the better of the two will be the one who greets the other first."
Reference: Sahih al-Bukhari 6077
In-book reference: Book 78, Hadith 105
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 73, Hadith 100