E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Pound of Flesh.
The whole bargain, the exact terms of the agreement, the bond literatim et verbatim. The allusion is to Shylock, in The Merchant of Venice, who bargained with Antonio for a pound of flesh, but was foiled in his suit by Portia, who said the bond was expressly a pound of flesh, and therefore (1) the Jew must cut the exact quantity, neither more nor less than a just pound; and (2) in so doing he must not shed a drop of blood.