Deuteronomy 8:20

20 as [the] heathen men perished, which the Lord did away in thine entering, so also ye shall perish, if ye shall be unobedient to the voice of your Lord God. (as the heathen shall perish, whom the Lord shall do away when thou shalt enter into the land, so also ye shall perish, if ye do not obey the voice of the Lord your God.)

Deuteronomy 8:20 Meaning and Commentary

Deuteronomy 8:20

As the nations which the Lord destroyeth before your face, so
shall ye perish
Be cut off by the sword, or cast out as they were, the same sins, particularly idolatry, being committed by them. This is to be understood of the seven nations of the land of Canaan, which the Lord would be gradually destroying when Israel came into the possession of their land; and they might righteously expect the same treatment, should they be guilty of the same sins:

because ye would not be obedient to the voice of the Lord your God;
expressed in his law, especially in the two first precepts of it, which require the worship of one God, and forbid the worshipping of idols; or to the Word of the Lord, as the Targum of Jonathan, Christ, the essential Word, in whom the name of the Lord was, and whose voice Israel was to obey, ( Exodus 23:20-22 ) .

Deuteronomy 8:20 In-Context

18 But think thou upon thy Lord God, that he hath given strengths to thee (to become prosperous), that he should fulfill his covenant, of which he swore to thy fathers, as this present day showeth. (But rather, remember the Lord thy God, that it is he who hath given thee the power to become prosperous, in order to fulfill his covenant which he swore to thy fathers, as he doeth in this present day.)

19 Forsooth if thou forgettest thy Lord God, and followest alien gods, and worshippest them in (thine) heart, and honourest [them] withoutforth, lo! now I before-say to thee, that thou shalt perish utterly; (But if thou forgettest the Lord thy God, and followest foreign, or other, gods, and worshippest them inwardly, and honourest them outwardly, lo! I now say to thee beforehand, that is, I warn thee, that thou shalt utterly perish;)

20 as [the] heathen men perished, which the Lord did away in thine entering, so also ye shall perish, if ye shall be unobedient to the voice of your Lord God. (as the heathen shall perish, whom the Lord shall do away when thou shalt enter into the land, so also ye shall perish, if ye do not obey the voice of the Lord your God.)