אַֽל־תִּפְחֲדוּ֙ וְאַל־תִּרְה֔וּ הֲלֹ֥א מֵאָ֛ז הִשְׁמַעְתִּ֥יךָ וְהִגַּ֖דְתִּי וְאַתֶּ֣ם עֵדָ֑י הֲיֵ֤שׁ אֱל֙וֹהַּ֙ מִבַּלְעָדַ֔י וְאֵ֥ין צ֖וּר בַּל־יָדָֽעְתִּי׃
Zittert nicht und fürchtet nicht; habe ich doch von jeher es dir verkündet und angesagt, und ihr seid meine Zeugen: Es gibt keinen Gott außer mir, und es ist kein Hort, den ich nicht kenne.
Rashi on Isaiah
and be not dismayed Heb. תִּרְהוּ. There is no similar word, and its interpretation according to its context is like תֵּחַתּוּ, be not dismayed from making My name known among the heathens (nations [K’li Paz and mss.]).
Ibn Ezra on Isaiah
אל תרהו Be ye not afraid, תרהו is hap. leg; those that identify it with תראו are wrong, on account of the absence of the radical י 10This is no good reason at all; since י of ירא to fear can in writing be well omitted in the future Kal; it is read תּׅ־רְאוּ to distinguish it from. תּׅרְאוּ you will see.—According to I. E. א and ה belong to those letters which interchange.—
Rashi on Isaiah
let you hear from Mount Sinai, and I told you there that there is no God besides Me.