Albert Barnes 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)

Though I walk in the midst of trouble - Though I am in the deep valley of sorrow, I will not be overlooked or forgotten. This implies that the writer was then in trouble, and it expresses the conviction that whenever he would be in trouble God would remember him, and give him life and strength.

Thou wilt revive me - You will cause me to live; you will give me life (Psalms 30:3). . The meaning is, You will give me life—vigor—strength—to bear the trouble.

Thou shalt stretch forth thine hand - As one does when he is about to inflict a blow.

Against the wrath of mine enemies ... - In reference to all their attempts to destroy me. You will meet their wrath by your power, and I will be safe.