Unquestionably, it is they who are the corrupters, but they perceive [it] not.
The Saheeh International Quran Translation
أَلَآ إِنَّهُمْ هُمُ ٱلْمُفْسِدُونَ وَلَٰكِن لَّا يَشْعُرُونَUnquestionably, it is they who are the corrupters, but they perceive [it] not.