Surah At-Tawbah, ayah 56

وَيَحۡلِفُونَ بِٱللَّهِ إِنَّهُمۡ لَمِنكُمۡ وَمَا هُم مِّنكُمۡ وَلَٰكِنَّهُمۡ قَوۡمٞ يَفۡرَقُونَ ٥٦

Wayahlifūna billāhi innahum laminkum wamā hum minkum walākinnahum qawmun yafraqūn

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