Śrīmad-Bhāgavatam · Text 11.20.3
Who is speaking and story frame
गुणदोषभिदादृष्टिमन्तरेण वचस्तव ।
नि:श्रेयसं कथं नृणां निषेधविधिलक्षणम् ॥ ३ ॥
guṇa-doṣa-bhidā-dṛṣṭim
antareṇa vacas tava
niḥśreyasaṁ kathaṁ nṝṇāṁ
niṣedha-vidhi-lakṣaṇam
Without seeing the difference between piety and sin, how can one understand Your own instructions in the form of Vedic literatures, which order one to act piously and forbid one to act sinfully? Furthermore, without such authorized Vedic literatures, which ultimately award liberation, how can human beings achieve the perfection of life?
Read the purport on Vedabase.ioFrom Canto 10, chapter 14 onward, the translation and purports were completed by Śrīla Prabhupāda's disciples after his departure, and published by the Bhaktivedanta Book Trust.