We shall now look for a moment at the remainder of our chapter, in which Moses, in words of intense earnestness, presses upon the congregation the urgent need of watchfulness and diligence in reference to all the statutes and judgments of the Lord their God. The beloved and faithful servant of God, and true lover of the people, was unwearied in his efforts to brace them up to that whole-hearted obedience which he knew to be at once the spring of their happiness and their fruitfulness; and just as our blessed Lord warns His disciples by setting before them the solemn judgment of the unfruitful branch, so does Moses warn the people as to the sure and terrible consequences of disobedience. "Take heed to yourselves, that _your heart be not deceived_, and ye turn aside, and serve other gods, and worship them." Sad progress downward! The heart deceived. This is the beginning of all declension. "And ye turn aside." The feet are sure to follow the heart. Hence the deep need of keeping the heart with all diligence; it is the citadel of the whole moral being, and so long as it is kept for the Lord, the enemy can gain no advantage; but when once it is surrendered, all is really gone,--there is the turning aside; the secret departure of the heart is proved by the practical ways,--"other gods" are served and worshiped. The descent down along the inclined plane is terribly rapid. "And then"--mark the sure and solemn consequences--"the Lord's wrath be kindled against you, and He _shut up the heaven_, that there be no rain, and that the land yield not her fruit; and ye perish quickly from off the good land which the Lord giveth you." What barrenness and desolation there must be when heaven is shut up! No refreshing showers coming down, no dew-drops falling, no communication between the heaven and the earth. Alas! how often had Israel tasted the awful reality of this! "He turneth rivers into a wilderness, and the water-springs into dry ground; a fruitful land into barrenness, for the wickedness of them that dwell therein."