وَمَا مَنَعَنَآ أَن نُّرۡسِلَ بِٱلۡأٓيَٰتِ إِلَّآ أَن كَذَّبَ بِهَا ٱلۡأَوَّلُونَۚ وَءَاتَيۡنَا ثَمُودَ ٱلنَّاقَةَ مُبۡصِرَةٗ فَظَلَمُواْ بِهَاۚ وَمَا نُرۡسِلُ بِٱلۡأٓيَٰتِ إِلَّا تَخۡوِيفٗا

Wa in min qaryatin illaa Nahnu muhlikoohaa qabla Yawmil Qiyaamati aw mu'az ziboohaa 'azaaban shadeedaa; kaana zaalika fil Kitaabi mastooraa

And We refrain from sending the signs, only because the men of former generations treated them as false: We sent the she-camel to the Thamud to open their eyes, but they treated her wrongfully: We only send the Signs by way of terror (and warning from evil).

— Al-Isra' (ٱلْإِسْرَاء), 17:59