Musnad Ahmad 30:3089

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, he said: I heard Sulayman narrating from Dhakwan, from Abu Hurayrah, from the Prophet, may Allah bless him and grant him peace, that he said: "Do not cut ties with one another, do not hate one another, do not envy one another, and do not turn your backs on one another. And be brothers, as Allah has commanded you."