John Calvin Commentary Isaiah 66:12

"For thus saith Jehovah, Behold, I will extend peace to her like a river, and the glory of the nations like an overflowing stream: and ye shall suck [thereof]; ye shall be borne upon the side, and shall be dandled upon the knees." — Isaiah 66:12 (ASV)

I cause peace to flow on her like a river. He continues his metaphor, comparing the children of God to infants who are carried in the arms and warmed in the bosom of their mothers, who even play with them. To express his affection toward us more strongly, he compares himself to a mother, whose love, as we have previously seen (page 30), greatly exceeds every other (Isaiah 49:15). The Lord wishes to be like a mother to us, so that, instead of the annoyances, reproaches, distresses, and anxieties we have endured, he may treat us gently and, as it were, fondle us in his bosom. By the word “peace” he means prosperity.

And the glory of the Gentiles as an overflowing torrent. The word “glory” contains a repetition, by which he denotes every kind of riches, so that nothing is lacking for full and perfect peace; for, since the Gentiles had previously lived luxuriously and had enjoyed a vast abundance of everything desirable, he affirms that all riches, and everything that belongs to a happy life, will be possessed by believers, as the rivers run into the sea.

By “constant flowing” he denotes continuity; for, since God is an inexhaustible fountain, his peace differs greatly from the peace of the world, which quickly passes away and dries up.

Therefore, whenever we behold the sad and melancholy condition of the Church, let us remember that these promises relate to us no less than to that people. Since the Lord has rivers of peace which he wishes to cause to flow into his Church, let us not despair even amidst the fiercest wars; but, in our distresses and hardships, let us take heart and rejoice.

When he takes pleasure in us as infants, and not as those of mature age, we should acknowledge our condition, so that we may be satisfied with such consolations. And indeed, it is a sign of remarkable condescension that he thus bears with our weakness.