Quran 33, Al-Ahzab (Confederates) ⓘ

33:5Proclaim their real parentage. That will be more equitable in the sight of Allah. And if ye know not their fathers, then (they are) your brethren in the faith, and your clients. And there is no sin for you in the mistakes that ye make unintentionally, but what your hearts purpose (that will be a sin for you). Allah is ever Forgiving, Merciful.

ادْعُوهُمْ لِآبَائِهِمْ هُوَ أَقْسَطُ عِنْدَ اللَّهِ فَإِنْ لَمْ تَعْلَمُوا آبَاءَهُمْ فَإِخْوَانُكُمْ فِي الدِّينِ وَمَوَالِيكُمْ وَلَيْسَ عَلَيْكُمْ جُنَاحٌ فِيمَا أَخْطَأْتُمْ بِهِ وَلَكِنْ مَا تَعَمَّدَتْ قُلُوبُكُمْ وَكَانَ اللَّهُ غَفُورًا رَحِيمًا