E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Civis Romanus Sum.
This single plea sufficed to arrest arbitrary condemnation, bonds, and scourging. Hence, when the centurion commanded Paul to be examined by scourging, he virtually pleaded Civis Romnus sum; and asked, Is it lawful for you to scourge a Roman citizen, and uncondemned? (1) No Roman citizen could be condemned unheard; (2) by the Valerian Law he could not be bound; (3) by the Sempronian Law it was forbidden to scourge him, or to beat him with rods. (See also Acts xvi. 37, etc.)