Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: A son can only fulfill the right of his father if he finds him as a slave, then buys him and sets him free.
Hadith Referenceالمنتقى ابن الجارود / كتاب الطلاق / 971
Hadith Gradingغلام مصطفےٰ ظهير امن پوري:صحيح
Hadith Takhrijاز غلام مصطفےٰ ظهير امن پوري:«صحيح مسلم : 1510۔»