The Blessed Lord said, “Among them, sattva, being pure is an illuminator – prakāsakam and is harmless. O sinless one, it binds through attachment to happiness – sukhasangena and attachment to knowledge – jnāna-sangena.
Know rajas to be of the nature of passion, born of hankering and attachment – trsnā-āsanga-samudbhavam. O son of Kunti, that rajas binds the embodied one through attachment to actions – karma-sangena.
On the other hand, know tamas, which deludes all embodied beings to be born of ignorance. O scion of Bharata dynasty, tamas binds through inadvertence, laziness and sleep – pramāda-ālasya-nidrābhih.
O scion of the Bharata dynasty, sattva attaches one to happiness, rajas to action, while tamas, covering up knowledge leads to inadvertence also.
O scion of the Bharata dynasty, sattva increases by subduing both rajas and tamas, rajas by overpowering sattva and tamas, and tamas by dominating over sattva and rajas.
[Chapter 14, Slokas 14.06 – 14.10]
Lord Krishna in the above verses speaks about the qualities of Nature but one needs to remember as the Lord has stated in the Thirteen Chapter, both Nature and the purusah – individual soul are without beginning and all modifications as also the qualities as born of Nature and as the purusah – soul is seated in Nature, it experiences the qualities born of Nature remaining as a non-agent and a witness and that all actions as being done in various ways by Nature itself.