Chapter 14 - Verse 8

तमस्त्वज्ञानजंविद्धि मोहनं सर्वदेहिनाम् ।
प्रमादालस्यनिद्राभिस्तन्निबध्नाति भारत ॥ ८ ॥

tamastvajñānajaṃviddhi mohanaṃ sarvadehinām .
pramādālasyanidrābhistannibadhnāti bhārata .. 8 ..


But, know thou Tamas to be born of unwisdom, deluding all embodied beings; by heedlessness, indolence and sloth, it binds fast, O Bharata.
Read the commentary

The third guna, Tamas, causes delusion or non-discrimination.

Again the action of the gunas is briefly described as follows: