Where is the description of the vow and the Bodhi tree?
This seems to appear in the Jhataka (in the Khuddaka-Nikâya) literature: THE ATTAINMENT OF BUDDHASHIP in J.i.7110 marked as p. 76.

Then the Future Buddha turned his back to the trunk of the Bo-tree and faced the east. And making the mighty resolution, &quot;Let my skin, and sinews, and bones become dry, and welcome! and let all the flesh and blood in my body dry up! but never from this seat will I stir, until I have attained the supreme and absolute wisdom!&quot; he sat himself down cross-legged in an unconquerable position, from which not even the descent of a hundred thunder-bolts at once could have dislodged him.
At this point the god Mâra, exclaiming, &quot;Prince Siddhattha is desirous of passing beyond my control, but I will never allow it!&quot; went and announced the news to his army, ...

The above page is linked/referenced on this index page as &quot;i.685-772 (§ 8.), Intro&quot;.