Where does the quote come from It is better to be the poor servant of a poor master?

It comes from Plato's work work "The Republic". There is a part named "The Allegory of the Cave".

Citation:

"And if they were in the habit of conferring honors among themselves on those who were quickest to observe the passing shadows and to remark which of them went before, and which followed after, and which were together; and who were therefore best able to draw conclusions as to the future, do you think that he would care for such honors and glories, or envy the possessors of them? Would he not say with Homer,

Better to be the poor servant of a poor master, and to endure anything, rather than think as they do and live after their manner?

- Yes, he said, I think that he would rather suffer anything than entertain these false notions and live in this miserable manner ."