Deuteronomy 2:6

Ye shall buy meat of them for money, that ye may eat; and ye shall also buy water of them for money, that ye may drink.

Cross-reference

In Deut 2:28, Moses repeats the same offer to pay for food and water when requesting passage from Sihon, showing consistent policy.

In Deut 2:29, Moses recalls that Edom and Moab allowed them to pass with payment—this is the precedent cited for the same request to Sihon.

In Numbers 20:19, Israel makes the same offer to pay for water when asking Edom for passage—a parallel request with the same terms.