pradyumnaḿ gadayā sīrṇa-
vakṣaḥ-sthalam ariḿ-damam
apovāha raṇāt sūto
dharma-vid dārukātmajaḥ
pradyumnam -- Pradyumna; gadaya -- by the club; sirna -- shattered; vakshah-sthalam -- whose chest; arim -- of enemies; damam -- the subduer; apovaha -- removed; ranat -- from the battlefield; sutah -- His chariot driver; dharma -- of his religious duty; vit -- the expert knower; daruka-atmajah -- the son of Daruka (Lord Krishna's driver).
Srila Visvanatha Cakravarti explains that actually Lord Pradyumna has a sac-cid-ananda body, an eternal, spiritual form that can never be wounded by mundane weapons. Daruka's son, however, was a great devotee of the Lord, and out of intense love he feared for the safety of his master and thus removed Him from the battlefield.
Srila Prabhupada writes, "The name of Salva's commander-in-chief was Dyuman. He was very powerful, and although bitten by twenty-five of Pradyumna's arrows, he suddenly attacked Pradyumna with his fierce club and struck Him so strongly that Pradyumna became unconscious. Immediately there was a roaring, 'Now He is dead! Now He is dead!' The force of the club on Pradyumna's chest was very severe, enough to tear asunder the chest of an ordinary man."