Islam stands for truth and justice. Prophet Muhammad ﷺ established a just society on the bases of these two fundamentals of Islam. He reformed the society in a way that is exemplary in human history. And, in the process, abolished many traditions and rectified false relationships that had been practised in the jahili (ignorant) Arab society. One such practice was adopting a child, naming him after the adoptive father and giving him the same rights as a biological son. As this practice affected the inheritance law and caused many family and social problems like relationship between the adopted son and the adoptive mother, or the adopted son and the daughter in the adoptive family, Islam abolished this practice.
Islam lays much emphasis on taking care of orphans. Prophet Muhammad ﷺ once said that a person who cares for an orphaned child will be close beside him in Paradise and gestured to show that this closeness would resemble two adjacent fingers on a single hand. But there is a stark difference between taking care of an orphan and adopting a child like one’s own biological child. The Qur’ān gives specific rules about the legal relationship between a child and his/her adoptive family. It reminds adoptive parents that they are not the child’s biological parents.
The Qur’ān (33:4-5) says: “…Nor has He made your adopted sons your (biological) sons. Such is (only) your (manner of) speech by your mouths. But Allah tells (you) the Truth, and He shows the (right) Way. Call them by (the names of) their fathers; that is more just in the sight of Allah. But if you know not their father’s (names, call them) your brothers in faith, or your trustees. But there is no blame on you if you make a mistake therein. (What counts is) the intention of your hearts. And Allah is Oft-Returning, Most Merciful.”
Zaid bin Harithah was a slave. Prophet Muhammad ﷺ freed and adopted him as son. People started calling him Zaid bin Muhammad. But, after the revelation of this verse, the Prophet strictly put this practice to an end. Thus, naming an adopted child after the adoptive father is a heinous sin. Bukhari, Muslim and Abu Daud have related on the authority of Saad bin Abi Waqqas that the Prophet ﷺ said: “Paradise is forbidden for the one who called himself son of another person than his own father.”
If and when a Muslim needs to adopt a child, he should take particular care that the identity of the child’s biological family is never hidden, the child’s ties with the biological family are never severed, the child retains his own biological family name and does not change his name to match that of the adoptive family. Also, an adopted child inherits from his biological parents, not automatically from the adoptive parents. And, when the child is grown, members of the adoptive family are not considered blood relatives and are therefore not mahram (a member of one’s family with whom marriage would be considered haram) to him.