Bamidbar 21:27

על כן (more lit., about this) — about this war which Sihon waged against Moab, יאמרו המשלים THEY THAT SPEAK IN PARABLES SAY — One of these was Balaam of whom it is said, (Numbers 23:7), "And he took up his parable”. המשלים THEY THAT SPEAK IN PARABLES — The plural המשלים refers to Balaam and his father Beor (see Rashi on Numbers 24:3). They said — באו חשבון “COME TO HESHBON”, — For Sihon had been unable to capture it, and he went and hired Balaam to curse it, and this is the meaning of what Balak said, (Numbers 22:6) “For I know (by what has already happened) that whomsoever thou blessest is blessed, [and whomsoever thou cursest is cursed]” (Midrash Tanchuma, Chukat 24). תבנה ותכונן IT WILL BE BUILT UP AND ESTABLISHED, [SIHON’S CITY] — Heshbon will be rebuilt under Sihon’s name to be his city.

עַל־כֵּ֛ן יֹאמְר֥וּ הַמֹּשְׁלִ֖ים בֹּ֣אוּ חֶשְׁבּ֑וֹן תִּבָּנֶ֥ה וְתִכּוֹנֵ֖ן עִ֥יר סִיחֽוֹן׃

Wherefore they who speak in similes say, Come to Ḥeshbon, let the city of Siĥon be built and established: