רֹעֶ֣ה אֵ֔פֶר לֵ֥ב הוּתַ֖ל הִטָּ֑הוּ וְלֹֽא־יַצִּ֤יל אֶת־נַפְשׁוֹ֙ וְלֹ֣א יֹאמַ֔ר הֲל֥וֹא שֶׁ֖קֶר בִּימִינִֽי׃ (ס)
He striveth after ashes, A deceived heart hath turned him aside, That he cannot deliver his soul, nor say: ‘Is there not a lie in my right hand?’
Rashi on Isaiah
[To] a provider [made] of ashes, a deceived heart has perverted him His heart, which was deceived, turned him aside to make for himself a provider of ashes. The image, half of which was burned and made into ashes, this fool says that it is his provider and patron. Another explanation: רוֹעֶה אֵפֶר is an expression of companionship. One who worships idols associates himself with the idol, which is ash.
Ibn Ezra on Isaiah
He feedeth on ashes. He is like a man who feedeth on ashes, that hurt and do no good. It may also be compared with Ephraim feedeth on wind (Hos. 12:2).33That is, he goes after vain things.
Rashi on Isaiah
and he shall not save [i.e.,] the misled one shall not save his soul, saying, “Is there not falsehood in my right hand?” and separate from it.