Quran

 33:5

ادْعُوهُمْ لِآبَائِهِمْ هُوَ أَقْسَطُ عِنْدَ اللَّهِ ۚ فَإِنْ لَمْ تَعْلَمُوا آبَاءَهُمْ فَإِخْوَانُكُمْ فِي الدِّينِ وَمَوَالِيكُمْ ۚ وَلَيْسَ عَلَيْكُمْ جُنَاحٌ فِيمَا أَخْطَأْتُمْ بِهِ وَلَٰكِنْ مَا تَعَمَّدَتْ قُلُوبُكُمْ ۚ وَكَانَ اللَّهُ غَفُورًا رَحِيمًا ﴿٥﴾

5. Call them after their fathers; that is more equitable before Allah. But if you do not know their fathers, then your brethren in faith and your friends. There is no blame on you if you make a mistake in it, barring what your hearts intent. Allah is Forgiving and Merciful.