The Lord liveth. God was known to Israel as "the living God" from the time of Moses (Deuteronomy 5:26). The epithet exalted him above all other so-called gods, who were not living. But it had also a very precious, absolute meaning.
God's life was the source of man's. It was through God (who had life in himself) breathing into man the breath of life that man became a living soul (Genesis 2:7). Hence "the living God" (Psalms 42:2) is "the God of our life" (Psalms 42:8).
And blessed be my Rock (see Psalms 18:1, Psalms 18:31). In blessing "his Rock," David blesses God for his qualities of firmness, steadfastness, and trustworthiness. And let the God of my salvation be exalted.
"The God of my salvation" is a favourite phrase with David (see Psalms 25:5; Psalms 27:9; Psalms 38:22; Psalms 51:14; Psalms 88:1). Other writers use it rarely. When David prays that the God of his salvation (i.
e. the God who continually saves him and preserves him) may be "exalted," he probably desires that he may be praised and honoured of all men.