19. And I will be glad in Jerusalem. He expresses more than in the preceding verse; for by these words he means that he not only will give to men ground for rejoicing, but even will be a partaker with them in that joy. So great is his love toward us, that he delights in our prosperity not less than if he enjoyed it along with us. And hence we obtain no small confirmation of our faith, when we learn that God is moved, and so powerfully moved, by such an affection toward us. If we are in painful and distressed circumstances, he says that he is affected by grief and sorrow; and, on the other hand, if our condition is pleasant and comfortable, he says that he takes great pleasure in our prosperity. Hence also we have formerly seen that “the Spirit of the Lord is sad and vexed,” (Isaiah 63:10,) when that order which he demands and approves is overturned and confounded; and in another passage he takes upon himself the character of a husband who is satisfied with the love of his wife. (Isaiah 62:5.)