Sunan Ibn Majah #2375 · The Chapters on Gifts

“Bear witness that I have given Nu'man such and such from my wealth.” He said: “Have you given all your children something like that which you have given to Nu'man?” He said: “No.” He said: “Then let someone other than me bear witness to that.” And he said: “Would you not like all your children to honor you equally?” He said: “Of course.” He said: “Then do not do this.”