Heshbon was the city of Sihon1 king of the Amorites,2 who had fought against the former king of Moab3 and had taken from him all his land as far as the Arnon.4
References for Numbers 21:26
That is why the poets say: "Come to Heshbon and let it be rebuilt; let Sihon's city be restored.
"Fire went out from Heshbon, a blaze from the city of Sihon.5 It consumed6 Ar7 of Moab, the citizens of Arnon's heights.8
References for Numbers 21:28
Woe to you, O Moab!9 You are destroyed, O people of Chemosh!10 He has given up his sons as fugitives11 and his daughters as captives12 to Sihon king of the Amorites.
References for Numbers 21:29