Tafsir of An-Nazi'at 79:34

This is the commencement of explaining their afterlife, following the statement of their worldly conditions in His words, Exalted and Majestic is He, "as an enjoyment..." The Fa (So) indicates the sequence of what follows upon what preceded, according to what has been said, as the word "enjoyment" suggests.

Al-Tamma (the overwhelming event) is the greatest of calamities, as it is derived from tamma, meaning "to rise/surpass," as mentioned in the proverb: "The valley flowed and overwhelmed (fata ma) the villages," and "The torrent came and overwhelmed (fata ma) the well." Its superiority over calamities refers to its dominance over them. It has been said that its description as "the greatest" (al-kubra) is for emphasis. If one interprets its being an tamma as its being overwhelming to the creatures—such that they are unable to repel it—then the description "greatest" would serve as a specification.

It has been said that its nature as tamma is in consideration of it overcoming and surpassing the calamities of the world they have known, and its being kubra is in consideration of it being the greatest of all calamities absolutely. Other views have also been expressed. You know that "the greatest overwhelming event" has become like a proper noun for the Day of Resurrection. It is narrated here from Ibn Abbas that it is one of its names. It is also narrated from him, and from al-Hasan, that it is the second blast (of the Trumpet).

Ibn Abi Shaybah and Ibn al-Mundhir recorded from al-Qasim ibn al-Walid al-Hamdani that it is the hour in which the people of Paradise are driven to Paradise and the people of the Fire are driven to the Fire. They also recorded from Amr ibn Qays al-Kindi that it is the hour in which the people of the Fire are driven to the Fire. Similar in meaning is the statement of Mujahid: "It is when they are shoved toward Malik, the keeper of Hell."