Musnad Ahmad 5:766

Aswad ibn Amir narrated to us, Sharik informed us, from Mansur, from Rib'i, from Ali, may Allah be pleased with him, who said: Some people from Quraysh came to the Prophet, may Allah bless him and grant him peace, and said: "O Muhammad, we are your neighbors and your allies, and some people from our slaves have come to you, not out of a desire for the religion, nor a desire for jurisprudence; they have only fled from our estates and our wealth, so return them to us." He said to Abu Bakr, may Allah be pleased with him: "What do you say?" He said: "They have spoken the truth; they are your neighbors." The face of the Prophet, may Allah bless him and grant him peace, changed. Then he said to Umar, may Allah be pleased with him: "What do you say?" He said: "They have spoken the truth; they are indeed your neighbors and your allies." The face of the Prophet, may Allah bless him and grant him peace, changed.