Psalms 7:10

David having lodged his appeal with God by prayer and a solemn profession of his integrity, in the former part of the psalm, in this latter part does, as it were, take out judgment upon the appeal, by faith in the word of God, and the assurance it gives of the happiness and safety of the righteous and the certain destruction of wicked people that continue impenitent. I. David is confident that he shall find God his powerful protector and Saviour, and the patron of his oppressed innocency (Psa 7:10): "My defence is of God. Not only, God is my defender, and I shall find him so; but I look for defence and safety in no other; my hope for shelter in a time of danger is placed in God alone; if I have defence, it must be of God." My shield is upon God (so some read it); there is that in God which gives an assurance of protection to all that are his. His name is a strong tower, Pro 18:10. Two things David builds this confidence upon: - 1. The particular favour God has for all that are sincere: He saves the upright in heart, saves them with an everlasting salvation, and therefore will preserve them to his heavenly kingdom; he saves them out of their present troubles, as far as is good for them; their integrity and uprightness will preserve them.

— Matthew Henry's Concise Commentary (public domain)

defence--literally, "shield" (Psa 5:12).

— Jamieson-Fausset-Brown Commentary (public domain)