John Calvin Commentary Isaiah 30:25

"And there shall be upon every lofty mountain, and upon every high hill, brooks [and] streams of waters, in the day of the great slaughter, when the towers fall." — Isaiah 30:25 (ASV)

And it shall come to pass. When the prophets describe the kingdom of Christ, they commonly draw metaphors from ordinary human life. For the true happiness of the children of God cannot be described in any other way than by presenting an image of those things that fall under our bodily senses, and from which people form their ideas of a happy and prosperous condition. It amounts, therefore, to this: those who obey God and submit to Christ as their king will be blessed.

Now, we must not judge this happiness by an abundance of outward blessings. Believers often endure a scarcity of these and yet, on that account, do not cease to be blessed. Instead, those expressions are allegorical and are adapted by the Prophet to our ignorance, so that through those things perceived by our senses, we may come to know those blessings whose excellence is so great and surpassing that our minds cannot comprehend them.

And on every high hill there shall be streams. When he says that “on the mountains” there will be “streams and rivulets,” he provides an even more striking view of the plenty and abundance with which the Lord will enrich His people. Water is not plentiful on the peaks of mountains, which are exceedingly dry; the valleys are indeed well moistened and abound in water, but it is very uncommon for water to flow abundantly on the tops of mountains.

Yet the Lord promises that it will be so, though it appears to be impossible. By this mode of expression, He foretells that under the reign of Christ, we will be happy in every respect. He indicates that there will be no place without an abundant supply of blessings of every kind, and that nothing will be so barren that it is not rendered fruitful by His kindness, so that everywhere we may be happy.

This is what we should actually experience if we were fully under the authority of Christ. We would plainly see His blessing on all sides if we sincerely and honestly obeyed Him; everything would proceed as we desire, and the whole world and everything in it would contribute to our comfort. However, because we are very far from yielding that obedience, we have only a slight taste of those blessings and enjoy them only to the extent that we have advanced in newness of life.

By the day of slaughter, denotes another mark of divine favor: that God will keep His people safe and sound from the violence of enemies. In this way, the Prophet gives credibility to the former prediction, for otherwise, it would have been difficult to believe that captives and exiles would enjoy such prosperity.

Here, therefore, he speaks of the slaughter of the wicked, as if he had said, “The Lord will not only do good to you but will also drive out your enemies.” It is generally thought that the Prophet now speaks of the defeat that befell the wicked King Sennacherib when he besieged Jerusalem (2 Kings 19:35; Isaiah 37:36).

But when I examine it more closely, I am more inclined to view this passage as referring to the destruction of Babylon, for although a vast multitude of people was slain when Sennacherib was shamefully put to flight, the people were still not delivered.

This reminds us that we should not despair, even though our enemies are very numerous and have an abundance of garrisons, troops, and fortifications, for the Lord can easily put them to flight and defend His Church. Let us not be terrified by their power or rage, or be discouraged because we are few in number, for neither their troops, nor their bulwarks, nor their rage and insolence will prevent them from falling into the hands of God.