Bhikkhusutta 1.7

1.7

upekkhāsambojjhaṅgaṃ bhāveti vivekanissitaṃ virāganissitaṃ nirodhanissitaṃ vossaggapariṇāmiṃ.

and equanimity, which rely on seclusion, fading away, and cessation, and ripen as letting go.