כִּֽי־הִנֵּ֤ה הַיּוֹם֙ בָּ֔א בֹּעֵ֖ר כַּתַּנּ֑וּר וְהָי֨וּ כָל־זֵדִ֜ים וְכָל־עֹשֵׂ֤ה רִשְׁעָה֙ קַ֔שׁ וְלִהַ֨ט אֹתָ֜ם הַיּ֣וֹם הַבָּ֗א אָמַר֙ יְהוָ֣ה צְבָא֔וֹת אֲשֶׁ֛ר לֹא־יַעֲזֹ֥ב לָהֶ֖ם שֹׁ֥רֶשׁ וְעָנָֽף׃
(4,1) PORQUE he aquí, viene el día ardiente como un horno; y todos los soberbios, y todos los que hacen maldad, serán estopa; y aquel día que vendrá, los abrasará, ha dicho SEÑOR de los ejércitos, el cual no les dejará ni raíz ni rama.
Rashi
For lo, the sun comes This instance of יוֹם is an expression of sun, for so did the Sages state that there will be no Gehinnom in the future, but the Holy One, blessed be He, will take the sun out of its case; the wicked will be punished thereby and the righteous will be healed thereby. That is the meaning of what is stated (verse 20): “And the sun of mercy shall rise for you who fear My Name, etc.”
Tze'enah Ure'enah
“For that day is at hand, burning like an oven” [3:19]. When the day will come to do judgment on the evildoers. That is to say, the Holy One will pull the sun out of the heaven and it will be a remedy for the righteous and the sun will cause the evildoers to be destroyed with their children.5Rashi, Malachi, 3:19.