John Calvin Commentary Isaiah 62:3

"Thou shalt also be a crown of beauty in the hand of Jehovah, and a royal diadem in the hand of thy God." — Isaiah 62:3 (ASV)

And you shall be a crown of glory. Isaiah proceeds with the same subject, and we need not wonder at this, for no one, judging by human standards, could have formed such vast conceptions and expectations. Besides, he intended to fix the hearts of believers on the kingdom of Christ. It was all the more necessary to adorn and magnify this kingdom with these illustrious titles because, until now, it was not only obscure but also at a great distance.

It was necessary to guard against a twofold danger: that the Jews, when they saw they were still very far from their former honor, might not, on the one hand, despise the grace of God, or, on the other hand, rest satisfied with mere beginnings and thus, by disregarding Christ, devote their whole attention to earthly advantages. The Prophet therefore reminds them that the return to their native country was merely the forerunner of that exalted rank to be expected at the manifestation of Christ.

Regarding the former clause, exiles and slaves could perceive nothing but grounds for despair when they saw the outward condition of things, since, after having returned and been restored to their country, they made very little progress in building the temple. Accordingly, he instructs them to look to God, that they may expect from him the glory which is concealed from human eyes. Knowing that they are dear and precious in his sight, they may be fully satisfied with this until he adorns them more abundantly by the hand of Christ.

And the diadem of the kingdom. He calls the Church God’s crown because God wishes that his glory should shine in us. In this, it is proper that we should see and admire the inconceivable goodness of God, since, even though we are by nature filthy and corrupted, and more abominable than the mire of the streets, yet he adorns us in such a manner that he wishes us to be “the diadem of his kingdom.” Let us therefore be stirred by this goodness of God to the desire of leading a holy life, so that his image may be more and more formed anew in us.