Albert Barnes Commentary Psalms 7:10

"My shield is with God, Who saveth the upright in heart." — Psalms 7:10 (ASV)

My defense is of God - The meaning here is that God was his protector, and that in his troubles he confided in Him. The original word here, as in (Psalms 3:3) and (Psalms 5:12), is “shield.” See the notes at those verses.

Which saves the upright in heart - whom He who searches the heart (Psalms 7:9) sees to be upright; or to be sincere, truthful, and just. The writer says that it is a characteristic of God that He saves or protects all such; and, conscious of his innocence of the charges against himself, he here appeals to Him on that ground, and confides in His protection because he sees that in this respect he was blameless.