Majjhima Nikaya 3:113
SUJATOYasmiṁ samaye, bhikkhave, bhikkhuno taṁ dhammaṁ paññāya pavicinato pavicayato parivīmaṁsaṁ āpajjato āraddhaṁ hoti vīriyaṁ asallīnaṁ, vīriyasambojjhaṅgo tasmiṁ samaye bhikkhuno āraddho hoti, vīriyasambojjhaṅgaṁ tasmiṁ samaye bhikkhu bhāveti, vīriyasambojjhaṅgo tasmiṁ samaye bhikkhuno bhāvanāpāripūriṁ gacchati.
At such a time, a mendicant has activated the awakening factor of energy; they develop it and perfect it.