Musnad Abu Ya'la al-Mawsili 117:189

Ishaq narrated to us, Hammad narrated to us, from Thabit, from Anas, that the Prophet (peace and blessings of Allah be upon him) saw a trace of yellow (saffron) and said: "What is this?" He said: "O Messenger of Allah, I have married a woman for the weight of a date stone of gold." He said: "May Allah bless you. Give a wedding feast (walimah), even if it is with a sheep."