Beware the fury of a patient man
Possible interpretation: The implication is that the anger of people who are normally slow to anger is, when it eventually comes, terrible.Note: beware (verb) = be careful about; be cautious; be aware of the dangers | fury (noun) = violent anger | patient (adj.) = able to wait without getting angry | Compare: "Patience provoked turns to fury."
Origin: Quotation from Publilius Syrus, a Latin writer of maxims in the 1st century BC. In the 17th century, British poet and dramatist John Dryden used it in "Absalom and Achitophel", generally considered to be the greatest political poem in the English language:
Must I at length the Sword of Justice draw?
Oh curst Effects of necessary Law!
How ill my Fear they by my Mercy scan,
Beware the Fury of a Patient Man.
The saying "Beware the fury of a patient man" warns us