سنن النسائي

It was narrated that An-Nu'man said: "My mother asked my father for a gift and he gave it to me. She said: 'I will not be contented until you ask the Messenger of Allah (ﷺ) to bear witness.' So my father took me by the hand, as I was still a boy, and went to the Messenger of Allah. He said: 'O Messenger of Allah, the mother of this boy, the daughter of Rawahah, asked me for a gift, and she wanted me to ask you to bear witness to that.' He said: 'O Bashir, do you have any other child apart from this one?' He said: 'Yes.' He said: 'Have you given him gifts like that which you have given to this one?' He said: 'No.' He said: 'Then do not ask me to bear witness, for I will not bear witness to unfairness.'"