Musnad Abu Ya'la al-Mawsili 246:9

Zuhayr narrated to us, Yazid bin Harun narrated to us, Muhammad bin Ishaq informed us, from al-Zuhri, from Sa'id bin al-Musayyib, from Jubayr bin Mut'im, who said: When the Messenger of Allah (may Allah bless him and grant him peace) distributed the share of the near kin between Banu Hashim and Banu al-Muttalib, I and Uthman came to him and said: "O Messenger of Allah, these are Banu Hashim; their merit is not denied due to the position in which Allah, the Mighty and Majestic, has placed you among them. What do you think of Banu al-Muttalib? You gave to them and withheld from us, yet we and they are in the same position regarding you." He said: "They did not separate from me in Jahiliyyah nor in Islam; Banu Hashim and Banu al-Muttalib are but one thing," and he interlaced his fingers.