John Calvin Commentary Isaiah 12:3

"Therefore with joy shall ye draw water out of the wells of salvation." — Isaiah 12:3 (ASV)

You shall draw waters with joy. In this verse he confirms what we have already noticed, that this chapter may be regarded as a seal to confirm the promise that He gave about the redemption of His people. As if he had said, “The salvation of God has been set before you, like a constantly running fountain, from which you can draw waters in abundance.” This is a very beautiful metaphor; for in this life nothing is more necessary than water; indeed, no kind of scarcity causes us more uneasiness or distress than a scarcity of water.

Thus, by a figure of speech in which a part is taken for the whole, he declares that everything necessary for supporting life flows to us from the undeserved goodness of God. And since we are empty and destitute of everything good, he appropriately compares the mercy of God to a fountain, which satisfies those who are thirsty and dry, refreshes those who are parched with heat, and revives those who are worn out with fatigue.

From the fountains of the Savior. This wording is more appropriate to this passage than if he had said, “from the fountains of God”; for it yields more consolation when we know that He is the author of our salvation, and therefore the Prophet has skillfully adapted this term to the situation in which it is placed.

Now, if this promise includes the whole of Christ’s reign, we ought constantly to apply it to our use. Let us therefore know that the goodness of God is held out to us, that we may be satisfied with it; for we ought to be like a dry and thirsty land, as the Psalmist says (Psalms 143:6), that we may desire the waters of the Lord.

This goodness of God is wonderful and beyond what could have been believed: He does not allow us to burn with unsatisfied desire, but presents a fountain from which we may draw abundantly. That fountain is Christ, in whom all God’s benefits are imparted to us; for out of his fullness, as John says, we all draw (John 1:16). It remains, therefore, that whenever we feel our need, we go directly to Him.