89:21
Nay! When the earth is pounded to powder,
The word dakk literally means “to pound or crush something into bits and pieces” (89:21). This refers to the earthquakes that will shatter the earth and reduce the mountains to dust, symbolizing the dissolution of the world. This marks the first stage of Resurrection. Once this stage ends, the second stage of Resurrection will commence. The repetition of the word dakkan emphasizes that there will be a series of earthquakes before the complete dissolution of the world.
References:
Shafi, Muhammad (2008). Maariful Quran. (Vol .8 surah 89 verse 21).