Did Buddha Return to Extreme Asceticism? Subject sounds simple, but let me explain why I'm asking. So Gautama joined the ascetic lifestyle and lived it to the most extreme. Then it dawned on him that he would eventually die never finding out the cause/solution to suffering.

Accounts I've seen then vary: He then got up and went begging in a village, other accounts say a farm boy with cattle found him and offered him food, and then there's that story of Sujata with the rice milk which Siddhartha accepted. Going a little further on the last account, he divided the rice milk into 49 potions for the next 49 days, after which he got up and went to the Bodhi Tree where he attained enlightenment. Usually the different stories I read have one or a mix of these events.

Now here's where I'm confused. By this point, the Future Buddha had tried extreme mortification, realized that wasn't working, returned to eating to sustain his life, went under the Bodhi Tree, then makes the vow to not leave again until he finds the answer, EVEN til his body is dried and shriveled. How does the Middle Way operate in this part of the story? Isn't he just returning to that previous practice he renounced? What am I missing here?

I suppose my analysis of Buddha's life is probably disorganized, but there are certain events and the order in which I find them that I cannot reconcile and make sense in my mind. If anyone can better explain to me this, that would be most appreciated.

PS
I've asked this elsewhere, and am getting some help, I'm just expanding the search.
By this point, the Future Buddha had tried extreme mortification, realized that wasn't working, returned to eating to sustain his life, went under the Bodhi Tree, then makes the vow to not leave again until he finds the answer, EVEN til his body is dried and shriveled.


The ascetic practices he did were the methods he thought would lead to some spiritual attainment. He thought that not eating and making his body weak could have some benefit. 

Going to the Bodhi tree and not leaving is not a method. He didn't think that the act of not leaving the shades of a certain tree was a particularly interesting practice on its own merit.

The vow is interpreted not as asceticism, but as resolution or commitment. Whether he really meant that he would die under the tree we can't tell, but by the time he took food, it's clear that he was giving up the idea of trying to inflict pain in his body as a means to spiritual progress. Finally, it's clear that the practices he undertook under the tree were not ascetic in nature.