Pound of flesh

The phrase "pound of flesh" refers to an insistence on receiving exactly what was owed or promised, even if it involves inflicting great harm or exacting revenge. It stems from Shakespeare's play "The Merchant of Venice," where a character named Shylock demands a literal pound of flesh as collateral for an unpaid debt. Thus, the phrase is often used metaphorically to describe an unyielding or relentless pursuit of what is due, even at the expense of another's well-being or happiness.