John Gill Commentary Deuteronomy 6:3

"Hear therefore, O Israel, and observe to do it; that it may be well with thee, and that ye may increase mightily, as Jehovah, the God of thy fathers, hath promised unto thee, in a land flowing with milk and honey." — Deuteronomy 6:3 (ASV)

Hear therefore, O Israel, and observe to do it ;
Or them, the commandments given them:

that it may be well with you ;
in body and estate:

and that you may increase mightily ;
not only in wealth and riches, but chiefly in numbers:

as the Lord God of your fathers has promised you ;
a promise of increase of numbers was frequently made to Abraham, Isaac, and Jacob; as that their seed should be as the stars of heaven, and as the dust of the earth, and the sand on the sea shore, innumerable; see (Genesis 15:5) (22:17) (25:4) (28:14) and this especially

in the land that flows with milk and honey ;
a very common periphrasis of the land of Canaan, because of the plenty of good things in it; see (Exodus 3:8) .