[124] "And how, bhikkhus, is a bhikkhu one who investigates in three ways (tividhūpaparikkhī)? Here, bhikkhus, a bhikkhu investigates by way of the elements (dhātu), investigates by way of the sense bases (āyatana), investigates by way of dependent origination (paṭiccasamuppāda). It is in this way, bhikkhus, that a bhikkhu is one who investigates in three ways. Bhikkhus, a bhikkhu who is skilled in the seven cases (sattaṭṭhānakusala) and who investigates in three ways is called, in this Dhamma and Discipline, a consummate one, one who has lived the holy life, a supreme person."
End of the Fifth Sutta.
6. Buddha Sutta
On the Cause of Becoming a Buddha
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.