Muhammad bin 'Abdullah bin Abi Ya'qub محمد بن عبد الله بن أبي يعقوب التميمي · Divorce (Kitab Al-Talaq)

A man got up and said: Messenger of Allah, so-and-so is my son; I had illicit intercourse with his mother in the pre-Islamic period. The Messenger of Allah (ﷺ) said: There is no unlawful claiming of paternity in Islam. What was done in pre-Islamic times has been annulled. The child is attributed to the one on whose bed it is born, and the fornicator is deprived of any right.