Tafsir of Ar-Rahman 55:64

Mudhammatan, being dark, because of the intense irrigation. Ibn Abbas said, "Mudhammatan means, they have become dark green because of extensive water irrigation.'' Muhammad bin Ka`b said:

مدهامتان

(Mudhammatan), "Full of greenery.''

فبٲي آﻻء ربكما تكذبان