Sunan An-Nasa'i

It was narrated from Anas that 'Abdur-Rahman bin 'Awf came with a trace of saffron on him, and the Messenger of Allah said:""What's this for?"" He said: ""I have married a woman."" He said: ""What dowry did you give?"" He said: ""The weight of a Nawah (five Dirhams) of gold."" He said: ""Give a Walimah (wedding feast) even if it is with one sheep