What is the religious ruling on attributing a child born of Zina to his biological father without the mother being married to him, and is it permissible for the man to attribute the child to himself without marrying its mother?

The husband must repent and sever his relationship with the foreign woman. A child born out of wedlock is attributed to his mother. If the biological father acknowledges the child, his lineage is established according to some scholars. The father's marriage to the child's mother after the birth does not affect the ruling on the child's lineage. This woman has no right to ask him to divorce his wife, and he should not divorce her for that reason. It is best for the husband to keep his family together.