+~
+ According to the sutras, numerous eons ago, when the Buddha was an ordinary
+being, he took rebirth in a hell realm. He suffered gravely there as a result
+of his past negative karma.
+ He and a companion were forced to pull a wheel of fire on which a wrathful
+hell-guard was sitting, holding a burning club with which to beat them. His
+companion was so weak that he couldn’t pull the wheel anymore. The hell-
+guard stabbed his companion with a burning trident. His companion kept crying
+loudly and bleeding profusely. At that moment, with strong love and
+compassion, the Buddha developed enlightened aspiration, a vow to take
+responsibility for helping his companion and all the suffering beings from the
+depth of his heart, and he became a bodhisattva for the first time.
+ The bodhisattva begged the hell-guard, "Please have a little mercy on my
+suffering companion." At that, in a rage the hellguard hit him with a
+burning trident. Because of the power of his strong compassion, the
+bodhisattva died and was liberated from the hell-realm. His evil deeds of
+many eons were purified instantly by the power of such enlightened aspiration.
+Thereafter, he started his journey toward the fully enlightened state of
+buddhahood.
+ -- Tulku Thondup, from "Incarnation: The History and Mysticism of the Tulku
+ Tradition of Tibet"
+