2.
The Discourse on the Rare
115.
"The manifestation of three things, monks, is rare in the world.
Which three?
The manifestation of a Truth-finder, a Worthy One, a Perfectly Enlightened One is rare in the world; a person who expounds the Teaching and discipline proclaimed by the Truth-finder is rare in the world; a grateful and thankful person is rare in the world.
The manifestation of these three things, monks, is rare in the world."
The second.