Sunan An-Nasa'i

An-Nu'man bin Bashir Al-Ansari narrated that his mother, the daughter of Rawahah, asked his father to give some of his wealth to her son. He deferred that for a year, then he decided to give it to him. She said:""I will not be pleased until you ask the Messenger of Allah to bear witness."" He said: ""O Messenger of Allah, the mother of this boy, the daughter of Rawahah, insisted that I give a gift to him."" The Messenger of Allah said: ""O Bashir, do you have any other children besides this one?"" He said: ""Yes."" The Messenger of Allah said: ""Have you given all of them a gift like that which you have given to this son of yours?"" He said: ""No."" The Messenger of Allah said: ""Then do not ask me to bear witness, for I will not bear witness to unfairness