For he established a testimony in Jacob - He ordained or appointed that which would be for a "witness" for him; that which would bear testimony to his character and perfections; that which would serve to remind them of what he was, and of his authority over them. Any law or ordinance of God is thus a standing and permanent witness in regard to his character as showing what he is.

And appointed a law in Israel - That is, He gave law to Israel, or to the Hebrew people. Their laws were not human enactments, but were the appointments of God.

Which he commanded our fathers ... - He made it a law of the land that these testimonies should be preserved and faithfully transmitted to future times. See Deuteronomy 4:9; Deuteronomy 6:7; Deuteronomy 11:19. They were not given for themselves only, but for the benefit of distant generations also.

For he established a testimony in Jacob,.... So the law is called, being a testification of the divine will, Exodus 25:16 and the Scriptures, the writings of the Old Testament, which testify of Christ, his person, office, sufferings, and death, Isaiah 8:20 and particularly the Gospel, which is the testimony of God, of our Lord Jesus Christ, and of his apostles, 2 Timothy 1:8 which bears witness to the love and grace of God in the salvation of men by Christ; to the dignity of Christ's person, to the fulness of his grace, to each of the offices and relations he bears and stands in to his people; to the virtue of his obedience, sufferings, and death; to redemption, righteousness, peace and pardon by him: this is established in the house of Jacob, as the Targum; in the church, which is the pillar and ground of truth, among the saints and people of God, to whom it is delivered, and by whom it will be kept, and with whom it will remain throughout all ages; for it is the everlasting Gospel:

and appointed a law in Israel; the law given on Mount Sinai was peculiar to them, and so were the word and oracles, they were committed to them; and not only the writings of Moses, but the prophets, are called the law, John 10:34, but the Gospel seems to be here meant; see Gill on Psalm 78:1, this was ordained before the world for our glory, and is put and placed in the hands and hearts of the faithful ministers of it, and is published among, and received by, the true Israel of God:

which he commanded our fathers that they should make them known to their children; that is, the testimony and the law, and the things contained in them; the Jewish fathers were frequently commanded to teach their children the law of Moses, Deuteronomy 4:9 and it was their practice to instruct them in the knowledge of the Scriptures, 2 Timothy 3:15, and it becomes Christian parents to bring up their children in the nurture and admonition of the Lord, by making known to them the principles of the Christian religion, and the truths of the Gospel, Ephesians 6:4.

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.

5. testimony-(Ps 19:7).

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.