It is narrated from Hazrat Nu'man (may Allah be pleased with him) that his father gave him a gift, then his father went to the service of the Holy Prophet (peace and blessings be upon him) and asked him to be a witness to it. The Holy Prophet (peace and blessings be upon him) said to him, "Have you given all your sons the same as you have given to him?" He replied, "No." So the Holy Prophet (peace and blessings be upon him) said, "Do not make me a witness to this, for I cannot be a witness to injustice."