John Calvin Commentary Psalms 114:1

"When Israel went forth out of Egypt, The house of Jacob from a people of strange language;" — Psalms 114:1 (ASV)

When Israel went out from Egypt—that exodus, being a remarkable pledge and symbol of God’s love for the children of Abraham, it is not surprising that it should be so frequently recalled. In the beginning of the psalm, the prophet informs us that the people whom God purchased at so great a price are no longer their own.

The opinion of certain expositors, that at that time the tribe of Judah was consecrated to the service of God, according to what is said in Exodus 19:6 and 1 Peter 2:9, appears to me foreign to the prophet’s design. All doubt about the matter is removed by what is added immediately after: God’s taking Israel under His rule, which is simply a repetition of the same sentiment in other words.

Judah, being the most powerful and numerous of all the tribes and occupying the chief place among them, here takes precedence over the rest of the people. At the same time, it is very evident that the honor which is specifically ascribed to them belongs equally to the whole body of the people. When God is said to be sanctified, it must be understood that the prophet is speaking after the manner of men, because, in Himself, God is incapable of increase or diminution. Judah is called his holiness, and Israel his dominion, because His holy majesty, which previously had been little known, secured the veneration of all who had witnessed the displays of His incredible power. In delivering His people, God erected a kingdom for Himself and obtained respect for His sacred name; if then they do not constantly reflect upon such a remarkable instance of His kindness, their insensibility is totally inexcusable.