Samattasutta

sn47.27:1.1 The same setting.

sn47.27:1.3 “Reverend, they speak of the one called ‘an adept’.

sn47.27:1.4 How is an adept defined?”

sn47.27:1.5 “Reverends, an adept is someone who has completely developed the four kinds of mindfulness meditation.