,las las 'jig rten sna tshogs skyes,
,de ni sems pa dang des byas,
Karma causes the multitude of worlds.
Karma is movement of mind and what it brings about. KHS
From karma are various worlds born.
It's volition and what that creates. DKC
From: Abhidharmakosha by Vasubandhu, Chapter 4, verse 1.