אַל־תִּירָא֙ כִּ֣י עִמְּךָ־אָ֔נִי אַל־תִּשְׁתָּ֖ע כִּֽי־אֲנִ֣י אֱלֹהֶ֑יךָ אִמַּצְתִּ֙יךָ֙ אַף־עֲזַרְתִּ֔יךָ אַף־תְּמַכְתִּ֖יךָ בִּימִ֥ין צִדְקִֽי׃
זאָלסט ניט מורא האָבן, װאָרום איך בין מיט דיר, זאָלסט זיך ניט אומקוקן, װאָרום איך בין דײַן גאָט; איך שטאַרק דיך און איך העלף דיך, און איך לען דיך אונטערמיט דער רעכטער האַנט פֿון מײַן גערעכטיקײט.
Rashi
be not discouraged Heb. אַל תִּשְׁתָּע. Let your heart not melt like wax (שַׁעֲוָה). This is the rule: Every word whose first radical is ‘shin,’ when it is used in the reflexive present, past, or future, the ‘tav’ separates it and enters between the first two radicals. Comp. (infra 49:16) “And He was astounded (וַיַּשְׁתּוֹמֵם)”; (Micah 6:16) “For the statutes of Omri shall be observed (וְיִשְׁתַּמֵּר)”; (I Sam. 1: 14) “will you be drunk (תִּשְׁתַּכָּרִין)?”; (Job 30:16) “My soul is poured out (תִּשְׁתַּפֵּךְ).”
Ibn Ezra
תשתע The second ת is the characteristic of the Hithpael, correctly put after the first radical. אל תשתע Do not turn away.19See c. xvii. Note 11; c. xxii. Note 4.19See c. xvii. Note 11; c. xxii. Note 4. Comp. שעו מני turn away from me. (22:4)
Tze'enah Ure'enah
“Do not fear, for I am with you, I am your God, etc.” [41:10]. Do not be afraid, I am with you. Your heart should not dissolve like wax. I, God, will strengthen you and also help you, and will support you with My right hand, My justice.