भवाप्ययौ हि भूतानां श्रुतौ विस्तरशो मया। त्वत्तः कमलपत्राक्ष माहात्म्यमपि चाव्ययम् ॥

bhavāpyayau hi bhūtānāṁ śhrutau vistaraśho mayā tvattaḥ kamala-patrākṣha māhātmyam api chāvyayam

The production and destruction of beings have been heard by me in detail from Thee, O Lotus-eyed, and also Thy imperishable greatness.

In plain words: Arjuna says he has heard in detail from Krishna how all beings are born and die. He has also heard about Krishna's greatness, which never ends.