John Calvin Commentary Psalms 122:4

"Whither the tribes go up, even the tribes of Jehovah, [For] an ordinance for Israel, To give thanks unto the name of Jehovah." — Psalms 122:4 (ASV)

There the tribes ascended. David here invests Jerusalem with two titles of honor, calling it the sacred and regularly appointed place for calling upon the name of God, and next, the royal seat, to which the whole people were to turn for obtaining justice. All our salvation depends upon these two points: first, that Christ has been given to us to be our priest; and, secondly, that He has been established king to govern us.

God showed this to His ancient people symbolically. The sanctuary erected on Mount Zion was intended to keep their faith fixed upon the spiritual priesthood of Christ; and similarly, through the kingdom of David, an image of the kingdom of Christ was presented to them.

The Psalmist, therefore, says in the first place, that the tribes or families of God would come to Jerusalem; and then he immediately adds, that there the seat of judgment would be erected, on which he and his posterity will sit. The reason it was God's will that there should be only one temple and one altar was so that the people might not stray into various superstitions.

David therefore declares here that this place was appointed by God’s own mouth, so that all the families of God, or the twelve tribes, would assemble there from all directions. To express more plainly how important it was for this form of God’s worship to be preserved pure and complete, he says that it was for a testimony. The noun used comes from the verb עוד, ud, which signifies to bear witness, or to covenant. The word here denotes a mutual declaration or agreement between God and the people.

When the tribes come there, the Prophet essentially says, it will not be at random, as if led by their own fancy, but because God by His own mouth invites them. The point, therefore, is that the holy assemblies held at Jerusalem will not be vain and unprofitable, since God has made a covenant with His people, determining and appointing that place for His service.

From this we learn that in judging the true temple of God, it is necessary to take into account the doctrine taught. With respect to the time in which David lived, since God had adopted the Jewish people and it was His will that they should be employed in the external worship of His name, He prescribed to them a rule from which it was unlawful for them to deviate.

Thus, when the faithful assembled on Mount Zion, it was not foolishness, inconsiderate zeal, or the impulse of their own minds that brought them there—as if they resembled those people we daily see inventing for themselves, out of their own heads, countless kinds of divine worship. Instead, they were led there by the command of God, so that they might worship Him on Mount Zion. By this, the Prophet intimates that all other temples are unholy, and all other religions perverse and corrupt, because they do not correspond with the rule laid down in God’s Word.

He then adds the end of this contract or covenant, which was that the name of God might be praised. And, indeed, as yielding to God the glory of all good things is the end of our adoption, so it is the end of all our actions.