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.
يَا رَسُولَ اللَّهِ إِنَّ فُلاَنًا ابْنِي عَاهَرْتُ بِأُمِّهِ فِي الْجَاهِلِيَّةِ فَقَالَ رَسُولُ اللَّهِ ﷺ لاَ دِعْوَةَ فِي الإِسْلاَمِ ذَهَبَ أَمْرُ الْجَاهِلِيَّةِ الْوَلَدُ لِلْفِرَاشِ وَلِلْعَاهِرِ الْحَجَرُ