Chapter 14 - Verse 9

सत्त्वं सुखे सञ्जयति रजः कर्मणि भारत ।
ज्ञानमावृत्य तु तमः प्रमादे सञ्जयत्युत ॥ ९ ॥

sattvaṃ sukhe sañjayati rajaḥ karmaṇi bhārata .
jñānamāvṛtya tu tamaḥ pramāde sañjayatyuta .. 9 ..


Sattva attaches to happiness, Rajas to action, O Bharata, while Tamas, enshrouding wisdom, attaches, on the contrary, to heedlessness.
Read the commentary

Tamas, by its very nature as a veil, covers the judgment caused by Sattva and attaches one to heedlessness, i e., to the non-performance of necessary duties.

The mutual action of the gunas.

When do the gunas produce the effects described above?†
—The answer follows :

The question is: Do they produce their effects simultaneously, or at different times, each in its turn? In the former case, do they act in mutual concord or discord?—The answer is that they act at different times, each in its turn.—A.