Chapter 14 · The Three Qualities · Krishna said
Bhagavad Gita 14.9 — What the gunas do
सत्त्वं सुखे सञ्जयति रजः कर्मणि भारत। ज्ञानमावृत्य तु तमः प्रमादे सञ्जयत्युत ॥
sattvaṃ sukhe sañjayati rajaḥ karmaṇi bhārata | jñānamāvṛtya tu tamaḥ pramāde sañjayatyuta ||
Meaning
Sattva attaches one to happiness, rajas to action, while tamas covers knowledge and attaches one to negligence.