Ashwatthama became very angry when his father Dronacharya was killed in the Mahabharata war.

He send a very terrible weapon "Narayana Astra" on the Pandava army. Nobody could retaliate it. It used to attack people and immediately destroy those who had weapons in their hands and were seen trying to fight.

Lord Shri Krishna ordered the army to leave their weapons and keep hands folded silently.