What is the ruling regarding the action of my paternal uncle who committed adultery with a woman and fathered a child whom he registered in his name after marrying and divorating her? And should I treat this child as my cousin or a stranger, bearing in mind the principle: "The child belongs to the bed, and for the adulterer is the stone?"

If a man acknowledges a child born out of wedlock (walad al-zina) as his own, attributes him to himself, and registers him in official documents, then he becomes his son, and the rulings of lineage, such as inheritance and maintenance, apply to him. This is the opinion of some jurists, like Ibn Taymiyyah. No attention should be paid to the absence of a DNA test or the lack of resemblance between the child and the father's family. And if the man married with an unrecorded Fatihah ceremony, this does not negate her being a legitimate wife in Islamic law.