Differing grades
Sunan an-Nasa'i 3675
"I want to give this son of mine a slave as a present, and if you think that I should go ahead with it, I will go ahead." The Messenger of Allah said: "Have you given a present to all your children?" He said: "No." He said: "Then take (your present) back."
" أَكُلَّ بَنِيكَ نَحَلْتَهُ " . قَالَ لاَ . قَالَ " فَارْدُدْهُ "