Musnad Ahmad 652:32

Hashim narrated to us, Sayyar informed us, and Mughirah informed us, and Dawud informed us, from al-Sha’bi, and Isma’il ibn Salim, and Mujalid, from al-Sha’bi, from al-Nu’man ibn Bashir, who said: My father gave me a gift. Isma’il ibn Salim said from among the people: He gave him a slave. He said: My mother, ‘Amrah bint Rawahah, said to him: Go to the Prophet, may Allah bless him and grant him peace, and have him bear witness to it. He said: So he came to the Prophet, may Allah bless him and grant him peace, and mentioned that to him. He said: I have given my son, al-Nu’man, a gift, and ‘Amrah asked me to have you bear witness to that. He said: "Do you have children other than him?" He said: I said, yes. He said: "And have you given all of them the same as what you gave al-Nu’man?" He said: No. Some of these narrators said: "This is injustice." And some of them said: "This is coercion, so have someone other than me bear witness to this." Mughirah said in his narration: "Does it not please you that they should be equal in honoring you and kindness?" He said: Yes. He said: "Then have someone other than me bear witness to this." And Mujalid mentioned in his narration: "Indeed, they have a right upon you that you act justly among them, just as you have a right upon them that they honor you."