Sahih Muslim | Book 32 | Hadith Number 6210

Narrated by Abu Ayyub Ansiri
Abu Ayyub Ansiri reported Allah's Messenger (may peace be upon him) as saying: It is not permissible for a Muslim to have estranged relations with his brother beyond three nights, the one turning one way and the other turning the other way when they meet; the better of the two is one who is the first to give a greeting.