وَجَعَلْنَا فِي الْأَرْ‌ضِ رَ‌وَاسِيَ أَن تَمِيدَ بِهِمْ (And We created mountains on the earth, lest it should shake with them. 21:31) The word مَید (mayd) in Arabic language means to be convulsed. Therefore, the meaning of this verse is that Allah Ta` ala has planted mountains on the earth to hold it in place because any violent movement of the earth would be catastrophic to those who live on it.