Samantabhadra's Aspiration to Good Actions (Zangchö Mönlam)

This prayer is from the Avatamsaka (Flower Garland) Sutra (wyl. mdo phal po che) - one of the most important (and largest) of all Mahayana sutras. It includes the Sutra of the Ten Bhumis and the Gandavyuha Sutra, which in turn includes Samantabhadra's Aspiration to Good Actions. [ref]

"Thus have I heard. At one time the Bhagavan was at Sravasti in the Jeta grove, in the Anathapindada garden within a magnificent estate. He was with Samantabhadra, Manjushri and five thousand other bodhisattvas who had all undertaken the bodhisattva practice and aspirations of all-embracing good, Samantabhadra."

There, at Sravasti, begins the Gandavyuha Sutra, whose final pages are the "Extraordinary Aspiration of the Practice of Samantabhadra." Originally written in Sanskrit, the sutra was translated into Chinese beginning in the second century c.e. and into Tibetan toward the end of the first millennium. Virtually all Mahayana schools revere this sutra. In China, the Hwa Yen school of Buddhism was almost entirely devoted to the study of the Avatamsaka Sutra, of which the Gandavyuha Sutra is the last chapter.[ref]