John Gill Commentary Psalms 136:7

"To him that made great lights; For his lovingkindness [endureth] for ever:" — Psalms 136:7 (ASV)

To him that made great lights
For the inhabitants of the world to walk and work by, to do all the business of life in a comfortable manner; and which is an instance of mercy and goodness; see (Genesis 1:14–16) ;

for his mercy [endureth] for ever ;
these lights continuing for the benefit of mankind.