Ibn Ishaq محمد بن إسحاق بن يسار‎ · The Book of Presents

"Have you given all your children a present like that which you have given to him?" He said: "No." He said: "I will not bear witness to anything. Will it not please you if they were all to treat you with equal respect?" He said: "Of course." He said: "Then no (I will not do it)."