Al-Ahqaf 46:21

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

21. And mention, [O Muhammad], the brother of 'Aad, when he warned his people in the [region of] al-Ahqaf - and warners had already passed on before him and after him - [saying], "Do not worship except Allah. Indeed, I fear for you the punishment of a terrible day