כְּס֤וּס עָגוּר֙ כֵּ֣ן אֲצַפְצֵ֔ף אֶהְגֶּ֖ה כַּיּוֹנָ֑ה דַּלּ֤וּ עֵינַי֙ לַמָּר֔וֹם אֲדֹנָ֖י עָֽשְׁקָה־לִּ֥י עָרְבֵֽנִי׃
Gleich der Schwalbe und dem Kranich also zirpt ich, girrte Tauben gleich, ich erhob meine Augen zur Höhe: Herr, bedrängt bin ich, rette mich!
Rashi on Isaiah
like a crane (סוּס) same as (Jer. 8:7), סִיס, and that is the name of a bird.
Ibn Ezra on Isaiah
כסוס כעגור═כסוס עגור. Comp. כרע כאח לי as though he had been my friend, my brother (Ps. 35:14). In the same way ככבש כאלוף ═ אלוף ככבש like a lamb, like an ox (Jer. 14:19). סיס and עגור are names of birds, a crane, a swallow. So did I chatter. The patient in his heavy illness mutters and speaks what no one is able to understand.
Rashi on Isaiah
like a crane, a swallow like a crane and a swallow. (Alternatively,) like this bird, seized by the neck, and it screeches. So did Jonathan render: Like a crane that is caught and screeches.