“It’s because Bhāradvāja the Alms-Gatherer has developed and cultivated three faculties that he declares enlightenment: ‘I understand: “Rebirth is ended, the spiritual journey has been completed, what had to be done has been done, there is nothing further for this place.”’ What three? The faculties of mindfulness, immersion, and wisdom. It’s because Bhāradvāja the Alms-Gatherer has developed and cultivated these three faculties that he declares enlightenment. What’s the culmination of these three faculties? They culminate in ending. In the ending of what? Of rebirth, old age, and death. It’s because he sees that they culminate in the ending of rebirth, old age, and death that Bhāradvāja the Alms-Gatherer declares enlightenment: ‘I understand: “Rebirth is ended, the spiritual journey has been completed, what had to be done has been done, there is nothing further for this place.”’”

Linked Discourses 48.50 5. Old Age At Āpaṇa

So I have heard. At one time the Buddha was staying in the land of the Aṅgas, near the Aṅgan town named Āpaṇa. Then the Buddha said to Venerable Sāriputta: “Sāriputta, would a noble disciple who is sure and devoted to the Realized One have any doubt or uncertainty about the Realized One or his instructions?”

“Sir, a noble disciple who is sure and devoted to the Realized One would have no doubt or uncertainty about the Realized One or his instructions. You can expect that a faithful noble disciple will live with energy roused up for giving up unskillful qualities and embracing skillful qualities. They’re strong, staunchly vigorous, not slacking off when it comes to developing skillful qualities. For their energy is the faculty of energy.