Sattva attaches one to happiness, joins one to it; rajas to action, O Bhārata, the word 'attaches' carrying over. But tamas, having veiled, covered over, the discernment that sattva makes, attaches one to heedlessness by its own veiling nature; heedlessness is the not-doing of what has come to be the thing to be done. When do the qualities do the work described? It is told.

Sattva has attachment to happiness as its chief door; rajas has attachment to action as its chief door; but tamas, by veiling the knowledge of the truth of a thing and so being the cause of contrary knowledge, has as its chief door attachment to engagement in what is contrary to what is to be done. The qualities sattva and the rest are attendant on the own-form of nature transformed into the shape of the body. And, being attendant on the own-form, all of them are present at all times; so how do they beget mutually contrary effects? To this the Lord speaks.

This is a brief sub-gloss. For a fuller reading of this verse, see Madhusūdana, Śaṅkara, or Rāmānuja above.

He speaks with the word 'sattva'.