John Gill Commentary Psalms 56:11

"In God have I put my trust, I will not be afraid; What can man do unto me?" — Psalms 56:11 (ASV)

In God have I put my trust (See Gill on Psalms 56:4);

I will not be afraid what man can do unto me ;
the same with flesh in (Psalms 56:4) , and is opposed to God, in whom he trusted; and it suggests that he was not, and would not, be afraid of the greatest of men, as well as of the meanest; (See Gill on Psalms 56:4);

Arama distinguishes between "flesh" and "man"; the former, he says, means the Philistines, and the latter Saul and his army.