מִ֤י בָכֶם֙ יְרֵ֣א יְהוָ֔ה שֹׁמֵ֖עַ בְּק֣וֹל עַבְדּ֑וֹ אֲשֶׁ֣ר ׀ הָלַ֣ךְ חֲשֵׁכִ֗ים וְאֵ֥ין נֹ֙גַהּ֙ ל֔וֹ יִבְטַח֙ בְּשֵׁ֣ם יְהוָ֔ה וְיִשָּׁעֵ֖ן בֵּאלֹהָֽיו׃
Who is among you that feareth the LORD, That obeyeth the voice of His servant? Though he walketh in darkness, And hath no light, Let him trust in the name of the LORD, And stay upon his God.
Read Kabbalistic (mystical) interpretations of Isaiah 50:10: Zohar and classical Jewish mystical sources, free online.