“A pound of man’s flesh, taken from a man, is not estimable, nor profitable” – Explain.
This is a line spoken by Shylock, the Jewish moneylender in Act I, Scene 3. Antonio has come to try to borrow money from Shylock and Shylock (who has been mistreated by Antonio and therefore hates him) says he'll give the money free of interest but will take a pound of Antonio's flesh if he doesn't pay the money back.
The literal meaning of this line is that there's no value in a pound of human flesh, cut away from the man. Animal flesh can be sold, human flesh not.
As for how to interpret this in a larger sense -- it depends on your reading of Shylock. Is he really just doing this for a joke, or does he want to get revenge on Antonio?