Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
LXX

Deuteronomy 20:1

And if thou shouldest go forth to war against thine enemies, and shouldest see horse, and rider, and a people more numerous than thyself; thou shalt not be afraid of them, for the Lord thy God [is] with thee, who brought thee up out of the land of Egypt.

Read in other translations