Yahya related to me from Malik from Ibn Shihab from Anas ibn
Malik that the Messenger of Allah, may Allah bless him and grant him
peace, said, "Do not be angry with each other and do not envy each
other and do not turn away from each other, and be slaves of Allah,
brothers. It is not halal for a muslim to shun his brother for more
than three nights."
Muwatta Malik Book 47, Hadith 14