to ponder upon

He causes to grow for you thereby the crops, olives, palm trees, grapevines, and from all the fruits. Indeed in that is a sign for a people who give thought.
And He has subjected for you the night and day and the sun and moon, and the stars are subjected by His command. Indeed in that are signs for a people who reason.
And [He has subjected] whatever He multiplied for you on the earth of varying colors. Indeed in that is a sign for a people who remember.
(an-nahl : 11-13)