Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 6

Sanskrit:

तेभ्यः समभवत् सूत्रं महान् सूत्रेण संयुतः ।ततो विकुर्वतो जातो योऽहङ्कारो विमोहनः ॥ ६ ॥

ITRANS:

tebhyaḥ samabhavat sūtraṁmahān sūtreṇa saṁyutaḥtato vikurvato jātoyo ’haṅkāro vimohanaḥ

Translation:

From these modes arose the primeval sūtra, along with the mahat-tattva. By the transformation of the mahat-tattva was generated the false ego, the cause of the living entities’ bewilderment.

Purport:

According to Śrīla Śrīdhara Svāmī, sūtra is the first transformation of material nature that manifests the potency of activity, and it is accompanied by the mahat-tattva, which is endowed with the potency of knowledge. In the material world, one’s real knowledge is covered by fruitive activity and mental speculation. As one’s devotional service to the Lord slackens, these two tendencies grow automatically, just as the diminishing of light automatically brings an increase in darkness.