«Being your slave, what should I do but tend
Upon the hours and times of your desire?».
In Sonnet 57, the poet argues that he is not so much the young man’s friend as he is his slave. As a slave, he waits on the youth’s pleasure: “But, like a sad slave, stay and think of nought / Save where you are how happy you make those.”
Being your slave, what should I do but tend
Annoyed and sad underneath his dignified and polite phrasing, the poet seems to be losing the ability to think and judge critically: “So true a fool is love that in your will, / Though you do anything, he thinks no ill.” Ironically, these last two lines read more true if we substitute the poet for the word “love” and its pronoun “he”: “So true a fool am I in your will, / Though you do anything, I think no ill.” Following so closely after the soaring verse of Sonnet 55, the poet’s quick descent into self-pity makes his situation even more pathetic.
English audio from YouTube Channel Socratica
Summary from Cliffsnotes.com