Qur'ān 9:56 · At-Tawbah (التوبة)

وَيَحْلِفُونَ بِٱللَّهِ إِنَّهُمْ لَمِنكُمْ وَمَا هُم مِّنكُمْ وَلَـٰكِنَّهُمْ قَوْمٌۭ يَفْرَقُونَ

And they swear by Allah that they are from among you while they are not from among you; but they are a people who are afraid.