A Psalm of Asaph. Truly God is good to Israel, even to such as are of a clean heart. Truly God is good to Israel - Captives as they were, they still had many blessings from God; and they had promises of deliverance, which must be fulfilled in due time.
Such as are of a clean heart - Those who have a clean heart must have inward happiness: and, because they resemble God, they can never be forsaken by him.