However, the astonishing singular difficulty is not that they do not regress to lower attainments, but that they don the armor that resolves to establish innumerable sentient beings in buddhahood, while those beings whom they would guide are utterly non-apprehensible. Bodhisattvas who, for the sake of sentient beings, think they should don the armor of great compassion would as well think they should seek to do battle with space. If, when this is explained they are not discouraged, then they are practicing the transcendent perfection of wisdom, and, free from doubt, they will gradually come to rest on the irreversible levels, and attain omniscience.