Because Heshbon was the city of Sihon the king of the Amorites, who had fought against the former king of Moab and taken all his land out of his hand, to Arnon.
Your neck is like an ivory tower. Your eyes are like the pools in Heshbon, by the gate of Bath-rabbim. Your nose is like a tower of Lebanon which looks toward Damascus.
There is no more praise for Moab; in Heshbon they have devised evil against her: “Come and let us cut it off from being a nation!” Also you will be cut down, O Madmen. The sword will pursue you.
The fugitives stand without strength under the shadow of Heshbon; for a fire will come out of Heshbon and a flame from the midst of Sihon, and will devour the forehead of Moab and the crown of the head of the tumultuous ones.
Israel has lived in Heshbon and its nearby towns, in Aroer and its nearby towns, and in all the cities along the banks of the River Arnon for three hundred years. Why did you not take them back during that time?