78:5 For he established a {d} testimony in Jacob, and appointed a law in Israel, which he commanded our fathers, that they should make them known to their children:
(d) By the testimony and law, he means your law written, which they were commanded to teach their children, De 6:7.
78:5 Established - This is justly put in first place, as the chief of all his mercies. A testimony - His law, called a testimony, because it is a witness between God and men, declaring the duties which God expects from man, and the blessings which man may expect from God.
78:1-8 These are called dark and deep sayings, because they are carefully to be looked into. The law of God was given with a particular charge to teach it diligently to their children, that the church may abide for ever. Also, that the providences of God, both in mercy and in judgment, might encourage them to conform to the will of God. The works of God much strengthen our resolution to keep his commandments. Hypocrisy is the high road to apostacy; those that do not set their hearts right, will not be stedfast with God. Many parents, by negligence and wickedness, become murderers of their children. But young persons, though they are bound to submit in all things lawful, must not obey sinful orders, or copy sinful examples.