Tafsir of Al-Haqqah 69:4

Thumūd and ‘Ād denied the Striking Calamity (al-Qāri‘ah).

They denied the Resurrection, which strikes the people with terror and horrors. It is referred to as "the Striking Calamity" rather than using the pronoun [referring back to it] to emphasize the meaning of striking—which is the hitting of one thing against another—and to intensify [the description of] its terror.

The sky is [struck] by splitting and cleaving; the earth and the mountains by leveling and scattering; the stars by being blotted out and dimming.

This sentence is a resumption intended to explain some of the states of the "Striking Calamity" to him, peace and blessings be upon him, following the affirmation that no one had informed him about it. It explains that it is of such a nature that it is fitting to destroy those who deny it, as if it were said: "And what will make you know what the Striking Calamity is? Thumūd and ‘Ād denied it, and thus they were destroyed."