나비처럼 날아서 벌처럼 쏘다. (Nabi cheoreom naraseo beol cheoreom ssoda) Fly like a butterfly, sting like a bee.
Etymology
First attested in the Sohak eonhae (小學諺解 / 소학언해), 1585, as 톄로(Yale: thyeylwo). From Sino-Korean 톄 (體, tye, “manner, way”) and the postposition ―로 (ro, “in ..., by ...”).