Bhagavad Gita, Chapter 6, Verse 20-23

When the mind, absolutely restrained by the practice of concentration, attains quietude, and when seeing the Self by the self, one is satisfied in his own Self; when he feels that infinite bliss, which is perceived by the purified intellect and which transcends the senses, and established wherein he never departs from his real state; and having obtained which, regards no other acquisition superior to that, and where established, he is not moved even by heavy sorrow, let that be known as the state called by the name of Yoga, a state of severance from the contact of pain. This Yoga should be practised with perseverance, undisturbed by depression of heart.

Once the noise actually settles, something real underneath becomes visible, and it's stable enough to actually hold onto for good.

This describes an actual perceptual shift, not just calm for its own sake - a quieted mind lets someone genuinely see what was there all along. And this isn't a fleeting high: once that state is reached, it's described as something that doesn't slip away, even through real hardship.