﴿ ۞ وَٱذْكُرْ أَخَا عَادٍ إِذْ أَنذَرَ قَوْمَهُۥ بِٱلْأَحْقَافِ وَقَدْ خَلَتِ ٱلنُّذُرُ مِنۢ بَيْنِ يَدَيْهِ وَمِنْ خَلْفِهِۦٓ أَلَّا تَعْبُدُوٓا۟ إِلَّا ٱللَّهَ إِنِّىٓ أَخَافُ عَلَيْكُمْ عَذَابَ يَوْمٍ عَظِيمٍۢ ﴾

“AND REMEMBER that brother of [the tribe of] Ad, how - seeing that [other] warnings had already come and gone within his own knowledge as well as in times beyond his ken - he warned his people [who lived] among those sand-dunes: “Worship none but God! Verily, I fear lest suffering befall you on an awesome day!””

Please check ayah 46:25 for complete tafsir.