Surah Al-Inshiqaq 84:3

وَإِذَا ٱلْأَرْضُ مُدَّتْ

And when the earth has been extended

Translation: Saheeh International

Tafsir

and when the earth is stretched out when its width is increased just as a piece of leather is stretched so that no edifice or mountain remains upon it

Excerpt from Tafsir al-Jalalayn, commentary on 84:3, via Quran.com. The reader has the full commentary and 9 more tafsirs.