וַאֲנִ֤י אָמַ֙רְתִּי֙ לְרִ֣יק יָגַ֔עְתִּי לְתֹ֥הוּ וְהֶ֖בֶל כֹּחִ֣י כִלֵּ֑יתִי אָכֵן֙ מִשְׁפָּטִ֣י אֶת־יְהוָ֔ה וּפְעֻלָּתִ֖י אֶת־אֱלֹהָֽי׃
But I said: ‘I have laboured in vain, I have spent my strength for nought and vanity; Yet surely my right is with the LORD, And my recompense with my God.’
Rashi on Isaiah
And I said, I toiled in vain when I saw that I admonish them and they do not obey.
Rashi on Isaiah
Yet surely my right is with the Lord He knows that it is not from me but from them [i.e., He knows that their failure to obey is not due to my laziness, but to their obstinacy].