Charles Ellicott Commentary Isaiah 50:4

"The Lord Jehovah hath given me the tongue of them that are taught, that I may know how to sustain with words him that is weary: he wakeneth morning by morning, he wakeneth mine ear to hear as they that are taught." — Isaiah 50:4 (ASV)

The Lord God ... —A new section begins in the form of an abruptly introduced soliloquy. As in Isaiah 49:4, the speaker is the Servant of Jehovah, not Isaiah, though we may legitimately trace in what follows some echoes of the prophet’s own experience. The union of the two names Adonai Jahveh (or Jehovah) indicates, as elsewhere, a special solemnity.

The tongue of the learned. —Better, of a disciple, or, well-trained scholar.

That I should know how to speak. —Better, that I should know how to sustain (or, refresh) the weary with a word.

He awakens. —The daily teaching of the morning communion with God is contrasted by implication with the dreams and night visions of a less perfect inspiration. An illustration, perhaps a conscious fulfilment, may be found in Mark 1:35; Luke 4:42.

To hear as the learned. —Read disciples, as before. The true Servant is also as a scholar, studious of the Master’s will, as are other scholars.