יְהוָ֥ה חָנֵּ֖נוּ לְךָ֣ קִוִּ֑ינוּ הֱיֵ֤ה זְרֹעָם֙ לַבְּקָרִ֔ים אַף־יְשׁוּעָתֵ֖נוּ בְּעֵ֥ת צָרָֽה׃
O LORD, be gracious unto us; We have waited for Thee; be Thou their arm every morning, our salvation also in the time of trouble.
Rashi on Isaiah
Be their arm of the spoiled ones in the hand of the spoiler. (Note that we followed other editions of Rashi. Nach Lublin is erroneous in this passage.)
Ibn Ezra on Isaiah
O Lord, etc. This was to be the prayer of the righteous at the time of the invasion of the Assyrian king; the prayer is given here as a prophecy.
Rashi on Isaiah
every morning Daily, when they are in straits, also You be our salvation in time of trouble.