Charles Ellicott Commentary Deuteronomy 2:6

"Ye shall purchase food of them for money, that ye may eat; and ye shall also buy water of them for money, that ye may drink." — Deuteronomy 2:6 (ASV)

Ye shall buy meat ... and ... water. —Compare to Genesis 14:23, Lest thou shouldest say, I have made Abram rich, and Deuteronomy 15:1, I am thy shield, and thy exceeding great reward.