Majjhima Nikaya 3:117
SUJATOYasmiṁ samaye, bhikkhave, bhikkhuno pītimanassa kāyopi passambhati, cittampi passambhati, passaddhisambojjhaṅgo tasmiṁ samaye bhikkhuno āraddho hoti, passaddhisambojjhaṅgaṁ tasmiṁ samaye bhikkhu bhāveti, passaddhisambojjhaṅgo tasmiṁ samaye bhikkhuno bhāvanāpāripūriṁ gacchati.
At such a time, a mendicant has activated the awakening factor of tranquility; they develop it and perfect it.