The Lord God hath given me the tongue of the learned; literally, the tongue of disciples; i.e. a trained tongue, a well-taught tongue. Christ "did nothing of himself; as the Father had taught him," so he spoke (John 8:28).
That I should know how to speak a word in season to him that is weary; rather, that I shall know how to sustain by a word him that is weary. Compare, "Come unto me, all ye that labour and are heavy laden, and I will give you rest" (Matthew 11:28).
He wakeneth morning by morning … mine ear. God held immediate and constant communication with the "Servant"—not enlightening him occasionally, as he did the prophets, by dreams and visions, but continually whispering in his ear.
At no time did the Father "leave him alone" (John 8:29) or cease to speak to him. "Morning by morning" is not to be narrowed to the bare literal meaning, but to be taken in the sense of "un-interruptedly."
To hear as the learned; rather, to hear as disciples hear; i.e. attentively, submissively, gladly.