The happiness which at the outset, at the first contact, in the beginning of knowledge, dispassion, meditation, and absorption, is like poison, painful, because it demands the utmost effort, but in its ripening, born of the maturing of knowledge and dispassion, is like nectar, that happiness is declared by the wise to be of sattva. It is born of the clarity of the understanding turned to the self, the clearness, the limpidity like the transparency of water; or, the understanding being one that has the self for its object or rests on the self, it is born of the abundance of that understanding's clarity. For that reason it is of sattva.
Contemporary English rendering of the Sanskrit bhāṣya, pending scholar review.