Joshua 13:10 Midrash

וְכֹ֗ל עָרֵי֙ סִיחוֹן֙ מֶ֣לֶךְ הָאֱמֹרִ֔י אֲשֶׁ֥ר מָלַ֖ךְ בְּחֶשְׁבּ֑וֹן עַד־גְּב֖וּל בְּנֵ֥י עַמּֽוֹן׃

and all the cities of Sihon king of the Amorites, who reigned in Heshbon, unto the border of the children of Ammon;