II. God here promises that he will take them into covenant with himself. The sum of the covenant of grace we have, v. 28. You shall be my people, and I will be your God. It is not, "If you will be my people, I will be your God" (though it is very true that we cannot expect to have God to be to us a God unless we be to him a people), but he has chosen us, and loved us, first, not we him; therefore the condition is of grace, is by promise, as well as the reward; not of merit, not of works: "You shall be my people; I will make you so; I will give you the nature and spirit of my people, and then I will be your God." And this is the foundation and top-stone of a believer's happiness; it is heaven itself, Rev. xxi. 3, 7.