It is narrated from Sayyiduna Anas (may Allah be pleased with him) that he (the Prophet) (peace and blessings be upon him) saw a trace of yellow on Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) and asked: "O Abu Muhammad, what is this?" Abd al-Rahman said: O Prophet of Allah, I have married a woman for gold equal to the weight of a date stone. He (peace and blessings be upon him) said: "May Allah bless you; hold a wedding feast (walimah), even if only with one sheep."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13840