The Israelite victories over King Sihon of Heshbon and King Og of Bashan previewed the Hebrew conquest of Canaan. It came to represent God's promise to help his people when they were in need (see 13:10–12; Deuteronomy 2:24–3:7; Joshua 2:10; 9:10; 12:1–6; Judges 11:19–22; Nehemiah 9:22; Psalms 135:10–12; 136:17–22; Jeremiah 48:45–46).
Israel had left the wilderness before reaching Pisgah (compare Numbers 21:18, 23; 21:20). So, this story probably indicates an earlier event before the movement in 21:18–20.