The Sutra on the Original Vows and the Attainment of Merits of Ksitigarbha Bodhisattva, Chapter 1, Part 1 of 2

Ksitigarbha Bodhisattva is deeply respected and very well known for His vow to take responsibility for the instruction of all beings in the six worlds between the departure of Gautama Buddha and the rise of Maitreya, as well as His vow not to achieve Buddhahood until all hells are emptied. He is therefore often regarded as the Bodhisattva of hell-beings. The Sutra on the Original Vows of Ksitigarbha Bodhisattva is a Mahayana Sutra teaching about Ksitigarbha Bodhisattva and is one of the more popular Sutra in Buddhism. The Sutra tells of how Ksitigarbha became a Bodhisattva by making great vows to rescue other sentient beings and a description of how He displayed filial piety in His past lifetimes.