John Calvin Commentary Psalms 78:68

"But chose the tribe of Judah, The mount Zion which he loved." — Psalms 78:68 (ASV)

But he chose the tribe of Judah. The meaning is that God preferred the tribe of Judah to all the rest of the people and chose from it a king, whom he set over all the Israelites as well as the Jews. And he chose the mountain of Zion, appointing a certain spot on it to be the seat of his sanctuary.

So that the cause of this choice might not be sought anywhere else but in God, it is particularly stated that preferring Mount Zion to all other places, and enriching it in such a distinguished manner, proceeded entirely from the free and unmerited love of God.

The relative pronoun which is used here instead of the causal adverb for; the meaning is that the sanctuary of God was established there, not for any worthiness of the place, but solely because it was the good pleasure of God. It was proper that this second restitution of the people should be no less free than their first adoption was, when God made his covenant with Abraham, or when he delivered them from the land of Egypt.

God’s love for the place had people in view. From this it follows that the Church has been gathered together from the beginning, and in all ages, by the pure grace and goodness of God; for people have never been found to possess any intrinsic meritorious claims to his regard, and the Church is too precious to be left dependent on the power of people.