That obeyeth the voice of his servant. — The question may be asked of any servant of Jehovah, such as was Isaiah himself, but receives its highest application in the Servant who has appeared as speaking in the preceding verses.
That walketh in darkness. — The words grow at once out of the prophet’s own experience and that of the ideal Servant. All true servants know what it is to feel as if the light for which they looked had for a time failed them, to utter a prayer like that of Ajax, “Give light, and let us die” (Hom. Il. xvii. 647). The Servant felt it when he uttered the cry, “My God, my God, why hast thou forsaken me?” (Matthew 27:46). For such an one there were the words of counsel, “Trust, in spite of the darkness.” So the cry of the forsaken Servant was followed by the word “Father, into thy hands I commend my spirit” (Luke 23:46).