The Lord thy God will make thee plenteous in every work of thine hand, in the fruit of thy body, and in the fruit of thy cattle, and in the fruit of thy land, for good: for the Lord will again rejoice over thee for good, as he rejoiced over thy fathers: if thou shalt hearken unto the voice of the Lord thy God, to keep his commandments and his statutes which are written in this book of the law, and if thou turn unto the Lord thy God with all thine heart, and with all thy soul. For this commandment which I command thee this day, it is not hidden from thee, neither is it far off. . . . But the word is very nigh unto thee, in thy mouth, and in thy heart, that thou mayest do it. . . . I command thee this day to love the Lord thy God, to walk in his ways, and to keep his commandments and his statutes and his judgments, that thou mayest live and multiply: . . . for he is thy life, and the length of thy days. 

On the eve of entry into the Promised Land, Moses summarizes the abundant benefits God has given the Israelites and urges recommitment to their covenant with Him. Honoring the one God as their very life would be especially vital in Canaan, where worship of pagan deities was widespread. (The Hebrew verb šûb, to turn or return, occurs repeatedly in this chapter to emphasize the call to turn again to God—and God’s turning to His people.) 

That the “word” (meaning the entire Hebrew law) isn’t hidden assures listeners that God’s requirements are easy to understand, not mystical or obscure. “In thy mouth” alludes to reciting aloud as a customary way of learning.