עַל־כֵּן֙ מֵעַ֣י לְמוֹאָ֔ב כַּכִּנּ֖וֹר יֶֽהֱמ֑וּ וְקִרְבִּ֖י לְקִ֥יר חָֽרֶשׂ׃
Wherefore my heart moaneth like a harp for Moab, And mine inward parts for Kir-heres.
Ibn Ezra on Isaiah
Wherefore my heart, etc. These are not the words of the prophet, but of the Moabites, whom the prophet represents as speaking.