Deuteronomy 29:9

9 And ye shall take heed to do all the words of this covenant, that ye may understand all things that ye shall do.

Deuteronomy 29:9 Meaning and Commentary

Deuteronomy 29:9

Keep therefore the words of this covenant, and do them
To do which they were laid under great obligations, through the goodness of God to them, in giving them victory over the two kings, and delivering their countries into their hands, as well as by all the favours bestowed on them in the wilderness, where they were sufficiently supplied with food, drink, and raiment; all which is made use of as a motive and argument to engage them to observe and keep the covenant the Lord made with them:

that ye may prosper in all that ye do:
in all their occupations and businesses of life, in their manufactures and commerce, in the culture of their fields and vineyards, and in whatsoever they were employed in a lawful way; the word used has sometimes, the signification of acting wisely and prudently, as in ( Isaiah 52:13 ) ; hence the Septuagint version is, "that ye may understand all that ye do"; and so the Jerusalem Targum.

Deuteronomy 29:9 In-Context

7 And ye came as far as this place; and there came forth Seon king of Esebon, and Og king of Basan, to meet us in war.
8 And we smote them and took their land, and I gave it for an inheritance to Ruben and Gad, and to the half-tribe of Manasse.
9 And ye shall take heed to do all the words of this covenant, that ye may understand all things that ye shall do.
10 Ye all stand to-day before the Lord your God, the heads of your tribes, and your elders, and your judges, and your officers, every man of Israel,
11 your wives, and your children, and the stranger who is in the midst of your camp, from your hewer of wood even to your drawer of water,

The Brenton translation of the Septuagint is in the public domain.