וְלֹא־יָשִׁ֣יב אֶל־לִבּ֗וֹ וְלֹ֨א דַ֥עַת וְלֹֽא־תְבוּנָה֮ לֵאמֹר֒ חֶצְי֞וֹ שָׂרַ֣פְתִּי בְמוֹ־אֵ֗שׁ וְ֠אַף אָפִ֤יתִי עַל־גֶּחָלָיו֙ לֶ֔חֶם אֶצְלֶ֥ה בָשָׂ֖ר וְאֹכֵ֑ל וְיִתְרוֹ֙ לְתוֹעֵבָ֣ה אֶעֱשֶׂ֔ה לְב֥וּל עֵ֖ץ אֶסְגּֽוֹד׃
Rashi on Isaiah
And he does not give it thought [lit. and he does not return to his heart.] Half of it I burnt with fire.
Ibn Ezra on Isaiah
His heart. His intellect, which is the principal part of man.
Rashi on Isaiah
and he has neither knowledge nor understanding [lit. and there is neither knowledge nor understanding] in him to say this.