As for ʿAad, they were arrogant upon the earth without right and said, "Who is greater than us in strength?" Did they not consider that Allāh who created them was greater than them in strength? But they were rejecting Our signs.
A Warning to the Disbelievers and a Reminder of the Story of `Ad and Thamud
Allah says: `Say, O Muhammad, to these idolators who disbelieve in the message of truth that you have brought: If you turn away from that which I have brought to you from Allah, then I warn you of the punishment of Allah like the punishment that the past nations suffered for disbelieving in the Messengers.'
صَـعِقَةً مِّثْلَ صَـعِقَةِ عَادٍ وَثَمُودَ
(a Sa`iqah like the Sa`iqah which overtook `Ad and Thamud.) and other similar nations who did what they did,
The basic purpose of these verses is to warn the people of Makkah that if, even after seeing the manifest proofs of the Oneness of Allah, they do not accept the call of the Holy Prophet ﷺ ، they may face a punishment like the earlier people of ` Ad and Thamud had faced. In this context, a brief account of what happened to these people has been given. The people of Makkah are also reminded that their punishment on the Day of Judgment will be much more severe, and they will not be able to escape it, because even the organs of their body will testify against them. And in this context, some events of that Day are mentioned.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 14–17
Rejection of the call for Truth is the greatest crime in the eyes of God. If this rejection is of a call given by a prophet, the punishment for this starts right here in this world, just as happened in the case of the communities of ‘Ad and Thamud. The main point of the call for Truth has always been that man should become a worshipper of God. He should associate with the one and only God his feelings of fear and love. But in every age it has happened that the contemporaries of the Prophet opined that his personality was too unimpressive to have been chosen by God as His messenger. Therefore, they refused to accept his words.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.