Śrīmad-Bhāgavatam · Text 4.26.8
Who is speaking and story frame
अन्यथा कर्म कुर्वाणो मानारूढो निबध्यते ।
गुणप्रवाहपतितो नष्टप्रज्ञो व्रजत्यध: ॥ ८ ॥
anyathā karma kurvāṇo
mānārūḍho nibadhyate
guṇa-pravāha-patito
naṣṭa-prajño vrajaty adhaḥ
Otherwise, a person who acts whimsically falls down due to false prestige. Thus he becomes involved in the laws of nature, which are composed of the three qualities [goodness, passion and ignorance]. In this way a living entity becomes devoid of his real intelligence and becomes perpetually lost in the cycle of birth and death. Thus he goes up and down from a microbe in stool to a high position in the Brahmaloka planet.
Read Śrīla Prabhupāda's purport on Vedabase.io