עַל־כֵּ֛ן יֹאמְר֥וּ הַמֹּשְׁלִ֖ים בֹּ֣אוּ חֶשְׁבּ֑וֹן תִּבָּנֶ֥ה וְתִכּוֹנֵ֖ן עִ֥יר סִיחֽוֹן׃
그러므로 시인이 읊어 가로되 너희는 헤스본으로 올지어다 시혼의 성을 세워 견고히 할지어다
Rashi on Numbers
על כן (more lit., about this) — about this war which Sihon waged against Moab,
Sforno on Numbers
על כן יאמרו המושלים, the people who reveal the visions they have seen in their dreams and their interpretations of these visions, as did Bileam when his interpretation is introduced with the words וישא משלו (Numbers 23,7).
Rashbam on Numbers
על כן יאמרו המושלים, on account of the war against Sichon and Og they had prophesied in advance,