Isaiah 49:4-5
4
Then I said, I have laboured in vain, I have spent my strength for nought, and in vain: yet surely my judgment is with the LORD, and my work with my God.
5
And now, saith the LORD that formed me from the womb to be his servant, to bring Jacob again to him, Though Israel be not gathered, yet shall I be glorious in the eyes of the LORD, and my God shall be my strength.