16. This day the Lord thy God. He again reminds them that God is the author of the Law, in order that His majesty should the more impress them; and not only so, but that, since the Law was specially delivered to them, its observation was the more enjoined upon them. Hence he exhorts them earnestly to apply their hearts to those things which God had enjoined them to keep, because men grow careless in their duties, unless they are often stirred up. For, undoubtedly, God indirectly rebukes the people’s indifference, by so often calling them to obedience. By the words “with all thy soul” is meant serious apprehension, and carefulness, as well as sincerity, free from all disguise and deceit. For nothing is more displeasing to God than hypocrisy, because He seeth the heart. If any object that it was vain to demand of them what no mortal can perform, viz., to keep the Law with all their heart, I reply, that all the heart is opposed to a double or divided heart, and is equivalent to entire, or altogether without deceit, although (as we shall hereafter see) it is not absurd to propose to believers an object, at which they are to aim, although they may not attain to it as long as the weakness of the flesh hinders them.