What did the Buddha see under the Bo tree?

According to the Maha-Saccaka Sutta, the Buddha perceived (saw with his mind) three things:

http://www.accesstoinsight.org/tipitaka/mn/mn.036....

1. Rebirth

"I recollected my manifold past lives, i.e., one birth, two...five, ten...fifty, a hundred, a thousand, a hundred thousand, many eons of cosmic contraction, many eons of cosmic expansion, many eons of cosmic contraction & expansion: 'There I had such a name, belonged to such a clan, had such an appearance. Such was my food, such my experience of pleasure & pain, such the end of my life. Passing away from that state, I re-arose there. There too I had such a name, belonged to such a clan, had such an appearance. Such was my food, such my experience of pleasure & pain, such the end of my life. Passing away from that state, I re-arose here.' Thus I remembered my manifold past lives in their modes & details. This was the first knowledge I attained in the first watch of the night. Ignorance was destroyed; knowledge arose; darkness was destroyed; light arose — as happens in one who is heedful, ardent, & resolute."

2. Karma

"I saw — by means of the divine eye, purified & surpassing the human — beings passing away & re-appearing, and I discerned how they are inferior & superior, beautiful & ugly, fortunate & unfortunate in accordance with their kamma: 'These beings — who were endowed with bad conduct of body, speech, & mind, who reviled the noble ones, held wrong views and undertook actions under the influence of wrong views — with the break-up of the body, after death, have re-appeared in the plane of deprivation, the bad destination, the lower realms, in hell. But these beings — who were endowed with good conduct of body, speech & mind, who did not revile the noble ones, who held right views and undertook actions under the influence of right views — with the break-up of the body, after death, have re-appeared in the good destinations, in the heavenly world.' Thus — by means of the divine eye, purified & surpassing the human — I saw beings passing away & re-appearing, and I discerned how they are inferior & superior, beautiful & ugly, fortunate & unfortunate in accordance with their kamma. This was the second knowledge I attained in the second watch of the night. Ignorance was destroyed; knowledge arose; darkness was destroyed; light arose — as happens in one who is heedful, ardent, & resolute."

3. Four Noble Truths

" I discerned, as it was actually present, that 'This is stress... This is the origination of stress... This is the cessation of stress... This is the way leading to the cessation of stress... These are fermentations... This is the origination of fermentations... This is the cessation of fermentations... This is the way leading to the cessation of fermentations.' My heart, thus knowing, thus seeing, was released from the fermentation of sensuality, released from the fermentation of becoming, released from the fermentation of ignorance. With release, there was the knowledge, 'Released.' I discerned that 'Birth is ended, the holy life fulfilled, the task done. There is nothing further for this world.' This was the third knowledge I attained in the third watch of the night. Ignorance was destroyed; knowledge arose; darkness was destroyed; light arose — as happens in one who is heedful, ardent, & resolute."

Thanks for the question. May much peace and blessings be with you :)

The Buddha saw the ground and it was good, for it was dirt and all good Christians know man was made from it.

Nothing... there is no Buddha.

Only the God of the bible.

It was a chair painted red with flowers and pomegranates.

He found the path to enlightenment.