坐禪三昧經 2.55

2.55

If disgust gives rise to great compassion, pitying sentient beings who, on account of these empty bones, are far from nirvāṇa and enter the three bad destinies, [he vows:] 'I shall exert effort, cultivate virtues, and teach and transform sentient beings, making them understand that the body's marks are empty, bones covered with skin, truly an accumulation of impurity. For the sake of sentient beings, I shall gradually distinguish these marks of dharmas.' If there is a slight perception of purity, love and attachment arise in the mind; if there are many perceptions of impurity, disgust arises in the mind; because there are marks of dharmas that transcend, true dharmas arise. In the true mark of dharmas, there is neither pure nor impure, neither closure nor emergence; contemplating dharmas as equal, indestructible, and unshakeable—this is called the true mark of dharmas (transcending the arhat's dharma).