John Calvin Commentary Psalms 138:7

"Though I walk in the midst of trouble, thou wilt revive me; Thou wilt stretch forth thy hand against the wrath of mine enemies, And thy right hand will save me." — Psalms 138:7 (ASV)

Should I walk in the midst of trouble, etc. Here David declares the sense in which he looked for God to act as his preserver—by giving him life from the dead, if that were necessary. This passage well deserves our attention, for by nature we are so sensitively averse to suffering that we wish we might all live safely beyond the reach of its arrows, and we shrink from close contact with the fear of death as something completely unbearable.

At the slightest approach of danger, we are excessively afraid, as if our emergencies prevented the hope of God's deliverance. This is faith's true role: to see life in the midst of death and to trust God's mercy—not as that which will secure for us universal exemption from evil, but as that which will give us life in the midst of death every moment of our lives. For God humbles His children under various trials, so that His defense of them may be more remarkable, and so that He may show Himself to be their deliverer, as well as their preserver.

In the world, believers are constantly exposed to enemies, and David asserts that he will be safe under God’s protection from all their schemes. He declares his hope of life to lie in this: that the hand of God was stretched out for his help, that hand which he knew to be invincible and victorious over every foe. And from all this we are taught that it is God’s method to discipline His children with a continual conflict, so that, having one foot, as it were, in the grave, they may flee in alarm to hide themselves under His wings, where they may abide in peace. Some translate the particle אף (aph) as also, instead of anger, reading—thou wilt also extend over mine; enemies, etc. But I have followed the more commonly accepted meaning, as it is both fuller and more natural.