Śrīmad-Bhāgavatam · Text 3.9.31
Who is speaking and story frame
तत आत्मनि लोके च भक्तियुक्त: समाहित: ।
द्रष्टासि मां ततं ब्रह्यन्मयि लोकांस्त्वमात्मन: ॥ ३१ ॥
tata ātmani loke ca
bhakti-yuktaḥ samāhitaḥ
draṣṭāsi māṁ tataṁ brahman
mayi lokāṁs tvam ātmanaḥ
O Brahmā, when you are absorbed in devotional service, in the course of your creative activities, you will see Me in you and throughout the universe, and you will see that you yourself, the universe and the living entities are all in Me.
Read Śrīla Prabhupāda's purport on Vedabase.io