Chapter 31: The Book of Presents
It was narrated that 'Amir said: "I was told that Bashir bin Sa' d came to the Messenger of Allah and said: 'O Messenger of Allah, my wife 'Amrah bint Rawahah told me to give a gift to her son Nu' man, and she told me to ask you to bear witness to that.' The Prophet said: 'Do you have any other children?' He said: 'Yes.' He said: 'Have you given them something like that which you have given to this one?' He said: 'No.' He said: 'Then do not ask me to bear witness to unfairness.'"
Sunan an-Nasa'i 3683