Psalms 108:4 - Albert Barnes' Notes on the Bible

For thy mercy ... - This is taken from Psalms 57:10. The only change is in the expression “above the heavens,” instead of “unto the heavens.” The sense is essentially the same. The particular idea here, if it differs at all from the expression in Psalms 57:1-11, is, that the mercy of God seems to “descend” from heaven upon man, or “comes down” from on high.