One of the disputed points in the contemporary controversy on the nature of the Mosaic covenant has to do with the way Israel possessed the land of Canaan. Was it by faith, or by works? Was it by grace, or did it operate on a principle of merit?
John Calvin addressed this question extensively in his sermons on Deuteronomy, first published in English in 1583. Calvin's argument against the Roman Catholics is simple: if Israel could not merit earthly blessings in Canaan (types of heaven), how could they merit heaven itself? The former (earthly, typological blessings) were by grace through faith.
There is another pressing reason for giving attention to this short article, not to diminish Calvin's original purpose of writing against the Roman Catholics. There is in our day a number of Protestants who are proposing what is popularly called the "Two Kingdom" view, developed from the writings of Meredith Kline. One of the major contentions is that the covenant with Moses was actually a "republication" of the original "Covenant of Works" established between God and Adam. In short, it is a diminishing, or in some cases, a denial that the Mosaic Covenant was part of the Covenant of Grace.
You can read this article here: Calvin on Merit in the Land of Canaan