ישעיהו י:ט פירוש: רש״י ואבן עזרא

Is not Calno like Carchemish Just as the inhabitants of Carchemish are princes and governors, so are the inhabitants of Calno. Therefore, if not like Arpad, which is under the rule of Hamath, which I took from Aram, and if not like Damascus, that I took from Aram, so will I do to Samaria. “If not like Arpad of Hamath,” is the construct state, like Arpad of Hamath. Therefore, it is voweled with a ‘pattach’ [i.e., it reads אַרְפַּד rather than אַרְפָּד].

כלנו Kalno כלנה ═ Kalneh (Gen. 10:10); for the names mentioned there (Gen. x.) are names of places called after their founders, like מצרים Egypt.