Adding the last component of a guardian's surname to an orphan's name
Is it permissible to substitute the last component of my ward's full name with the fourth component of my full name?
It is permissible In Islamic law for the guardian of an orphan, man or woman, to add his/her family name to that of his ward who is an orphan or a child of unknown parentage. It is likewise permissible to change the last component of the child's full name to that of his guardian in a manner that shows the ward's affiliation to his guardian without deceiving the child or others that he is the guardian's biological offspring. The purpose is to remove the affiliation from the scope of adoption which is prohibited in Islamic law. Such an addition to the child's full name is tantamount to the bonds of loyalty between the Arabian tribes of old. This is permissible in Islamic law and achieves the child's interests in the different phases of his life though the principles of Islamic law concerning. adoption and its legal consequences must be preserved.
It is permissible to substitute the last component of the ward's full name with the fourth component of his guardian's name. This is not considered adoption which is forbidden in Islamic law.
Allah the Almighty knows best.