John Calvin Commentary Psalms 48:1

"Great is Jehovah, and greatly to be praised, In the city of our God, in his holy mountain." — Psalms 48:1 (ASV)

Great is Jehovah, and greatly to be praised. Before mentioning that special example of God's favor towards them, to which I have referred, the prophet teaches in general that the city of Jerusalem was happy and prosperous because God had graciously taken upon Himself the responsibility of defending and preserving it.

In this way, he separates and distinguishes the Church of God from all the rest of the world. When God selects from among the whole human race a small number whom He embraces with His fatherly love, this is an invaluable blessing that He bestows on them. His wonderful goodness and righteousness shine forth in the government of the whole world, so that no part of it is lacking His praise; indeed, we are everywhere provided with abundant reasons to praise Him.

Here, however, the inspired poet celebrates the glory of God, which is manifested in the protection of the Church. He states that Jehovah is great, and greatly to be praised in the holy city. But is He not so also in the whole world? Undoubtedly, He is. As I have said, there is no corner so hidden that His wisdom, righteousness, and goodness do not penetrate. However, since it is His will that these attributes should be manifested chiefly and in a particular manner in His Church, the prophet very properly sets before our eyes this mirror, in which God gives a clearer and more vivid representation of His character.

By calling Jerusalem the holy mountain, he teaches us, in one word, by what right and through what means it uniquely became the city of God. It was so because the ark of the covenant had been placed there by divine appointment. The meaning of the expression is this: If Jerusalem is, so to speak, a beautiful and magnificent theater on which God desires the greatness of His majesty to be seen, this is not due to any merits of its own. Rather, it is because the ark of the covenant was established there by God’s command as a token or symbol of His special favor.