The Buddha shares on the three kinds of persons who arise in the world for the welfare of the many - 1) the Tathāgata, 2) the Arahant, and 3) the trainee.
Bahujanahita sutta - The Welfare Of The Many
This was said by the Blessed One, said by the Arahant, and Thus have I heard:
"There are three kinds of persons who arise in the world for the welfare of the many, for the good of the many, out of compassion for the world, for the benefit, welfare, and good of gods and humans. What three? Here, bhikkhus, a Tathāgata, an Arahant, a perfectly enlightened Buddha arises in the world, accomplished in true knowledge and conduct, fortunate, knower of the worlds, unsurpassed trainer of persons to be trained, teacher of gods and humans, the enlightened one, the Blessed One. He teaches the Dhamma that is beneficial in the beginning, beneficial in the middle, and beneficial in the end, with both the meaning and the phrasing; he proclaims the spiritual life that is entirely complete and pure. This, bhikkhus, is the first kind of person who arises in the world for the welfare of the many, for the good of the many, out of compassion for the world, for the benefit, welfare, and good of gods and humans.
Again, bhikkhus, a disciple of that same teacher is an Arahant with taints exhausted, who has lived the spiritual life, done what had to be done, laid down the burden, achieved the highest goal, exhausted the fetters of existence, and is completely liberated through right wisdom. He teaches the Dhamma that is beneficial in the beginning, beneficial in the middle, and beneficial in the end, with both the meaning and the phrasing; he proclaims the spiritual life that is entirely complete and pure. This, bhikkhus, is the second kind of person who arises in the world for the welfare of the many, for the good of the many, out of compassion for the world, for the benefit, welfare, and good of gods and humans.
Further, bhikkhus, a disciple of that same teacher who is a trainee, on the path, learned, and endowed with virtuous conduct. He also teaches the Dhamma that is beneficial in the beginning, beneficial in the middle, and beneficial in the end, with both the meaning and the phrasing; he proclaims the spiritual life that is entirely complete and pure. This, bhikkhus, is the third kind of person who arises in the world for the welfare of the many, for the good of the many, out of compassion for the world, for the benefit, welfare, and good of gods and humans. These three kinds of persons, bhikkhus, arise in the world for the welfare of the many, for the good of the many, out of compassion for the world, for the benefit, welfare, and good of gods and humans."
The Blessed One spoke on this matter. In this regard, it is said:
"Indeed, the teacher, the first great seer in the world, his follower, a disciple with a developed mind; And another, on the path, still in training, learned and endowed with virtuous conduct.
These three, the best among gods and humans, illuminators, expounding the Dhamma; They open the door to the deathless state, releasing many people from their bonds.
Who, guided by the unsurpassed teacher, follow the well-taught path; Here itself, they make an end to suffering, those diligent in the Blessed One's teaching."
This matter too was spoken by the Blessed One, as I have heard.