Surah Al-Ahqaf, ayah 21

۞ وَٱذۡكُرۡ أَخَا عَادٍ إِذۡ أَنذَرَ قَوۡمَهُۥ بِٱلۡأَحۡقَافِ وَقَدۡ خَلَتِ ٱلنُّذُرُ مِنۢ بَيۡنِ يَدَيۡهِ وَمِنۡ خَلۡفِهِۦٓ أَلَّا تَعۡبُدُوٓاْ إِلَّا ٱللَّهَ إِنِّيٓ أَخَافُ عَلَيۡكُمۡ عَذَابَ يَوۡمٍ عَظِيمٖ ٢١

Wadhkur akhā 'ādin idh andhara qawmahū bil-ahqāfi waqad khalatin-nudhuru mim bayni yadayhi wamin khalfihī allā ta'budū illallāha innī akhāfu 'alaykum 'adhāba yawmin 'azīm

And mention, [O Muḥammad], the brother of ʿAad,¹⁴⁸⁴ when he warned his people in [the region of] al-Aḥqāf - and warners had already passed on before him and after him - [saying], "Do not worship except Allāh. Indeed, I fear for you the punishment of a terrible day."¹⁴⁸⁵