Śrīmad-Bhāgavatam · Text 11.20.2
Who is speaking and story frame
वर्णाश्रमविकल्पं च प्रतिलोमानुलोमजम् ।
द्रव्यदेशवय:कालान् स्वर्गं नरकमेव च ॥ २ ॥
varṇāśrama-vikalpaṁ ca
pratilomānulomajam
dravya-deśa-vayaḥ-kālān
svargaṁ narakam eva ca
According to Vedic literature, the superior and inferior varieties found in the human social system, varṇāśrama, are due to pious and sinful modes of family planning. Thus piety and sin are constant points of reference in the Vedic analysis of the components of a given situation — namely the material ingredients, place, age and time. Indeed, the Vedas reveal the existence of material heaven and hell, which are certainly based on piety and sin.
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.