Musnad Abu Ya'la al-Mawsili 129:64

Abu Khaythama narrated to us, Mu'adh ibn Mu'adh narrated to us, Humayd narrated to us, from Anas ibn Malik, who said: When Abd al-Rahman ibn Awf arrived as an emigrant, the Messenger of Allah (may Allah bless him and grant him peace) established brotherhood between him and Sa'd ibn al-Rabi'. Sa'd said to him, "I have wealth, so I will divide it in half for you. And I have two wives, so look at whichever of them is most beloved to you, and I will divorce her. When her waiting period ends, you marry her." Abd al-Rahman said to him, "May Allah bless your family and your wealth for you. Direct me to the market." He (Anas) said: The Messenger of Allah (may Allah bless him and grant him peace) missed him for some days, then he came to him, and upon him was the trace of yellow (saffron). The Messenger of Allah (may Allah bless him and grant him peace) said, "What is this?" He said, "I have married a woman from the Ansar." He said, "What did you give her as a dowry?" He said, "A date-pit's weight of gold, or the weight of a date-pit of gold." The Messenger of Allah (may Allah bless him and grant him peace) said, "Give a wedding feast, even if with a sheep."