। ॥ २४१ ॥
In plain words
Whoever fell at the hands of Kṛṣṇa, the joy of the Yadus, never came back to birth again — not once. So of all the avatāras, Kṛṣṇa is the one seated within them, the one who sets them moving.
Close to the Sanskrit
Those who were slain by the delight of the Yadus — they indeed did not attain rebirth again any more. Therefore Kṛṣṇa is the inner controller, the one who sets in motion, of the avatāras.