אִמְרוּ֙ לְנִמְהֲרֵי־לֵ֔ב חִזְק֖וּ אַל־תִּירָ֑אוּ הִנֵּ֤ה אֱלֹֽהֵיכֶם֙ נָקָ֣ם יָב֔וֹא גְּמ֣וּל אֱלֹהִ֔ים ה֥וּא יָב֖וֹא וְיֹשַׁעֲכֶֽם׃
Say to them that are of a fearful heart: ‘Be strong, fear not’; Behold, your God will come with vengeance, With the recompense of God He will come and save you.
Read halakhic rulings (Jewish law) on Isaiah 35:4: and classical halakhic sources.