Deuteronomy 4:46

4:46 in the Transjordan, in the valley opposite Beth Peor, in the land of King Sihon of the Amorites, who lived in Heshbon. (It is he whom Moses and the Israelites attacked after they came out of Egypt.

Deuteronomy 21:4

21:4 and bring the heifer down to a wadi with flowing water, to a valley that is neither plowed nor sown. There at the wadi they are to break the heifer’s neck.