2 Samuel 22:3

The God of my rock = my strong God: but it is better to alter the vowel points and read as in the Ps., "my God, my Rock." The title Rock is frequently used to describe the strength, faithfulness, and unchangeableness of God. See Deuteronomy 32:4; Deuteronomy 32:37; 1 Samuel 2:2; Psalms 28:1, &c.

in him will I trust Better, in whom I take refuge: carrying on the metaphor of a hiding-place in the rocks. Quoted in Hebrews 2:13; cp. Psalms 94:22.

my shield Compare God's promise to Abram (Genesis 15:1); and Deuteronomy 33:29.

the horn of my salvation The Power which saves and delivers me. The figure of the horn, as a symbol of victorious strength, is derived from horned animals. Cp. Deuteronomy 33:17; Luke 1:69.

and my refuge, &c. The words, "and my retreat, my saviour, thou savest me from violence," are omitted in Psalms 18.