سُبْحَانَ ٱللَّٰهِ
Holy Qur'an
Al-Qur'an
Kids Qur'an
This is obviously the meaning of the term sihr in the present context (see surah {74}. note [12]).
Perhaps they had said that the Hereafter was a fake, mere old wives' tales! If they had given serious thought to the Signs of Allah, they would have been saved from that serious spiritual blindness: then they will see that the fault was their own, and that the warnings of the messengers of Truth were nothing but pure Truth.