וּבָ֧א עָלַ֣יִךְ רָעָ֗ה לֹ֤א תֵדְעִי֙ שַׁחְרָ֔הּ וְתִפֹּ֤ל עָלַ֙יִךְ֙ הֹוָ֔ה לֹ֥א תוּכְלִ֖י כַּפְּרָ֑הּ וְתָבֹ֨א עָלַ֧יִךְ פִּתְאֹ֛ם שׁוֹאָ֖ה לֹ֥א תֵדָֽעִי׃
Vendrá pues sobre ti mal, cuyo nacimiento no sabrás: caerá sobre ti quebrantamiento, el cual no podrás remediar: y destrucción que no sabrás, vendrá de repente sobre ti.
Rashi on Isaiah
you shall not know how to remove it by prayer Heb. לֹֹא תֵדְעִי שַׁחְרָהּ. You shall not know to pray about it (Jonathan). Whom will you beseech to extricate you therefrom?
Ibn Ezra on Isaiah
יום רעה═רעה A day of evil.15A. V., Evil. I. E. supplies יום the day of because of the masculine form of the verb ובא.
Rashi on Isaiah
to rid yourself of it Heb. כַּפְּרָהּ, to wipe it away and to remove it, and this is every expression of atonement (כַּפָּרָה). It is an expression of wiping and taking away.