John Gill Commentary Deuteronomy 8:13

"and when thy herds and thy flocks multiply, and thy silver and thy gold is multiplied, and all that thou hast is multiplied;" — Deuteronomy 8:13 (ASV)

And when your herds and your flocks multiply
Having good pasture for them in so fruitful a land:

and your silver and your gold is multiplied ;
by trading with other nations:

and all that you have is multiplied ;
children, servants, and substance.