Why did the Buddha touch the earth at his enlightenment? At the Buddha's enlightenment, he pointed to the earth or touched the earth, meaning the earth (or world) was adequate witness to his spiritual accomplishment or new status, or, perhaps the only witness that would be acceptable to Mara. Mara accepted the witness. I do not understand the principle or truth of this event. Earth or the world seems to be personified in some way, or endowed with a capacity to accept or reject a plea for witnessing. Explanations and clarifications would be greatly appreciated. Thx.
PaPa, I believe touching the earth is a later addition to pali cannon, but i could be wrong.  Bodhirajakumara Sutta is one of the best sutta of autobiography of Bhudda.  Buddha also told Ven Anuruddha in dozens of sutta about himself from the history of sakaya clan, when he came down from Dusita into his mother's womb and so on to after the evening of enlightment.  

http://tipitaka.wikia.com/wiki/Bodhirajakumara_Sutta