Surah At-Taubah (The Repentance), Verse 56

وَیَحْلِفُوْنَ بِاللّٰهِ اِنَّهُمْ لَمِنْكُمْ وَمَا هُمْ مِّنْكُمْ وَلٰكِنَّهُمْ قَوْمٌ یَّفْرَقُوْنَ ۟

Wa yahlifoona billaahi innnahum laminkum wa maa hum minkum wa laakinnahum qawmuny yafraqoon

“They swear by Allah that they are indeed of you; but they are not of you: yet they are afraid (to appear in their true colours).”

Quran 9:56 (Yusuf Ali Translation)