David counted on God to defend him as a shield, since God saves the upright in heart, and David was upright. His confidence lay also in God"s righteous character. God would judge justly, and injustice touches His heart as well as His head. Even though God does not always judge as quickly as His people want, injustice does not escape His eye, and one day He will judge righteously (cf. 2 Peter 3:9). In view of this, we can leave vengeance up to Him ( Romans 12:19; Hebrews 10:30). [source][source][source]