Where does it say that Visnu..., I mean Krsna, is the source of Visnu from the srutis?

Expressions researched:
"where does it say that Visnu..., I mean Krsna, is the source of Visnu from the srutis"

1976 Conversations and Morning Walks

Śruti... Brahmā said, īśvaraḥ paramaḥ kṛṣṇaḥ (Bs. 5.1).

Morning Walk -- January 6, 1976, Nellore:

Mahāmṣa: (break) ...oṁ tad viṣṇoḥ paramaṁ padam. That claims Viṣṇu as the Supreme, but where does it say that Viṣṇu..., I mean Kṛṣṇa, is the source of Viṣṇu from the śrutis?

Prabhupāda: Śruti... Brahmā said, īśvaraḥ paramaḥ kṛṣṇaḥ (Bs. 5.1).

Acyutānanda: Brahma-saṁhitā is śruti.

Prabhupāda: Yes. Brahmā spoke śruti, Vedas, so whatever he speaks is śruti. It is therefore called saṁhitā. Saṁhitā means Vedas, śruti. As soon as it is called saṁhitā, that is Vedas.