Reference for Isaiah 66:15

כִּֽי־הִנֵּ֤ה יְהוָה֙ בָּאֵ֣שׁ יָב֔וֹא וְכַסּוּפָ֖ה מַרְכְּבֹתָ֑יו לְהָשִׁ֤יב בְּחֵמָה֙ אַפּ֔וֹ וְגַעֲרָת֖וֹ בְּלַהֲבֵי־אֵֽשׁ׃

For, behold, the LORD will come in fire, and His chariots shall be like the whirlwind; to render His anger with fury, And His rebuke with flames of fire.

ספר השרשים