The word Buddha comes from budh, to be completely aware, and was translated into Chinese [as] "to perceive, be awake, and gnosis". The original meaning is "to flourish".
What did Buddha become aware of under the Bodhi-tree? No sutra tells us. No book on Buddhism informs us.
Mahakasyapa was one of the Ten Great Disciples of Buddha. Each was supposed to have a special talent.. Mahakasyapa - Discipline.
"The monks were all silent. So were Buddha and Kasyapa, but with a difference."
Mumonkan, Case Six, The Buddha's Flower
People always ask for the answers. There is very little knowledge to be gained by simply asking. KNOCK and the door will be opened, SEEK and you will find... those are doing words, not talking words. People always ask, "What did Buddha see under that tree?" "What did your face look like before you were born?"
I told someone once that I'd got as far as the nose, and drew a picture of it. This did not seem to satisfy. Beware the easy answer, it is a lie. Beware the one who offers it. If you are going to begin a spiritual journey of self learning and self teaching, pack light.
I've got a million of these. They are all the same. That's why Gutei stuck with the finger thing. It's faster.