My father brought me to Allah's Messenger (ﷺ) and said: I have donated this slave to my son. whereupon he said: Have you made (such) donation to every one or your sons? He said: No. Thereupon he (the-Holy Prophet) said: Then take him back.
The Book of Gifts - Sahih Muslim 1623 b
In the name of Allah, the Most Gracious, the Most Merciful. This narration from Sahih Muslim addresses the important Islamic principle of justice and equal treatment among children in matters of gifting and inheritance.
Commentary on the Hadith
The Prophet Muhammad (peace be upon him) rejected this specific donation because it violated the fundamental Islamic principle of justice ('adl) among children. When a father gives gifts to his children, he must treat them equally to prevent envy, hatred, and family discord.
This ruling applies specifically to voluntary gifts, not obligatory inheritance which has its own prescribed shares in the Quran. The wisdom behind this prohibition is to maintain family harmony and prevent preferential treatment that could lead to resentment among siblings.
Scholars have derived from this hadith that if a parent wishes to give extra to a particular child due to special circumstances (such as illness, disability, or greater need), this should be done discreetly and with valid justification that doesn't constitute unfair preference.
Legal Rulings Derived
The majority of scholars hold that it is obligatory (wajib) for parents to maintain equality among children in gifting, except with legitimate reason.
If unequal gifting has occurred, the parent must rectify the situation by either retrieving the excess gift or compensating other children equally.
This ruling applies to both sons and daughters, though some scholars differentiate based on inheritance shares in certain cases.