Devadahvagga

Suttapiṭaka · Majjhimanikāya · Vol. 14 · Section 22

[22] Furthermore, bhikkhus, with the fading away of rapture (pīti), a bhikkhu dwells in equanimity (upekkhā), mindful (sato) and clearly comprehending (sampajāno), and he experiences pleasure with the body; he enters and dwells in the third jhāna, of which the noble ones declare: "He is equanimous, mindful, one who dwells in pleasure." Thus too, bhikkhus, exertion is fruitful, striving is fruitful.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.