The Venerable Ānanda explains the four paths to arahantship.
Yuganaddha sutta - In Tandem
Thus have I heard - At one time, the Venerable Ānanda was dwelling in Kosambi, at Ghosita's park. There the Venerable Ānanda addressed the bhikkhus: "Friends, bhikkhus."
"Friend," those bhikkhus replied to the Venerable Ānanda.
The Venerable Ānanda said this: "Friends, whoever, whether a bhikkhu or a bhikkhunī, declares the attainment of arahantship in my presence, they all do so by one of these four paths, or by one of them.
What are these four?
1 Here, friends, a bhikkhu develops discernment preceded by tranquility. As he develops discernment preceded by tranquility, the path arises in him. He pursues that path, develops it, and cultivates it. As he does so, the fetters are abandoned and the underlying tendencies are eliminated.
2 Again, friends, a bhikkhu develops tranquility preceded by discernment. As he develops tranquility preceded by discernment, the path arises in him. He pursues that path, develops it, and cultivates it. As he does so, the fetters are abandoned and the underlying tendencies are eliminated.
3 Again, friends, a bhikkhu develops tranquility and discernment in tandem. As he develops tranquility and discernment in tandem, the path arises in him. He pursues that path, develops it, and cultivates it. As he does so, the fetters are abandoned and the underlying tendencies are eliminated.
4 Again, friends, a bhikkhu's mind is seized by agitation about the Dhamma. There comes a time when his mind becomes internally steadied, calmed, unified, and collected. The path arises in him. He pursues that path, develops it, and cultivates it. As he does so, the fetters are abandoned and the underlying tendencies are eliminated.
Friends, whoever, whether a bhikkhu or a bhikkhunī, declares the attainment of arahantship in my presence, they all do so by one of these four paths, or by one of them."