Surah Ali 'Imran — Ayah 24 (3:24)
ذَٰلِكَ بِأَنَّهُمۡ قَالُواْ لَن تَمَسَّنَا ٱلنَّارُ إِلَّآ أَيَّامٗا مَّعۡدُودَٰتٖۖ وَغَرَّهُمۡ فِي دِينِهِم مَّا كَانُواْ يَفۡتَرُونَ ٢٤
English translation (Saheeh International)
That is because they say, "Never will the Fire touch us except for [a few] numbered days," and [because] they were deluded in their religion by what they were inventing.
Brief commentary
They turned away from the truth and ignored it because they used to think that the fire of Hell will only touch them for a few days and they will then enter Paradise. This belief deceived them and made them bold against Allah and His religion.