בְּ֭עֵת יְזֹרְב֣וּ נִצְמָ֑תוּ בְּ֝חֻמּ֗וֹ נִדְעֲכ֥וּ מִמְּקוֹמָֽם׃
בעת זײ װערן צעװאַרעמט, װערן זײ פֿאַרשװוּנדן, װי עס װערט הײס, צעגײען זײ פֿון זײער אָרט.
Rashi
At the time they become warm Heb. יזרבו, an expression of יְצֹרָבוּ, they become warm from the heat of the sun.
Rashi
they retreat Heb. נצמתו, retrait in Old French, shrink, contract, as “and the vinegar shrinks them (צומתן), (Pesachim 41a) in Talmudic Hebrew. [In the word יְזֹרָבוּ], the “zaddi” is converted to a “zayin,” like צעקה and זעקה, a cry.
Rashi
[Therefore,] יְזֹרָבוּ is an expression of (Ezekiel 21:3), “and all faces shall be scorched (ונצרבו),” and like (Prov. 16:27), “searing (צרבת) fire.”