The Śūraṅgama Sūtra, Volume Five: Ucchuṣma among the Twenty-five Sages' Methods of Perfect Penetration

Original text: 乌刍瑟摩。于如来前。合掌顶礼佛之双足。而白佛言。我常先忆。久远劫前。性多贪欲。有佛出世。名曰空王。说多淫人。成猛火聚。教我遍观百骸四肢。诸冷暖气。神光内凝。化多淫心成智慧火。从是诸佛皆呼召我。名为火头。我以火光三昧力故。成阿罗汉。心发大愿。诸佛成道。我为力士。亲伏魔怨。佛问圆通。我以谛观。身心暖触。无碍流通。诸漏既销。生大宝焰。登无上觉。斯为第一。

Explanation: Ucchuṣma came before the Buddha, pressed his palms together and bowed at the Buddha's feet, and said to the Buddha: I often recall that, long ago, countless kalpas ago, my disposition was full of greed and desire. There was a Buddha who appeared in the world, named King of Space Buddha (Ākāśa-rāja Buddha), who told me that where people abundant in lust are born, great fierce fires often gather, burning them with the fire of desire. He also taught me to contemplate thoroughly every day in meditation the vital energies throughout the hundred skeletal parts and four limbs of my body, observing whether each was cold or warm. In the course of this contemplative practice (vipaśyanā-caryā), meditative concentration arose, the mind's spirit coalesced inward and no longer scattered outward; the lustful mind was extinguished, and the mind of wisdom was born. I became adept at transforming the lustful mind into the fire of wisdom, and from then on all the Buddhas called me "Fire Head." By the power of the fire-light samādhi that I realized, I became a great arhat. Thereupon I made a great vow: whenever the Buddhas attain the Way, I would serve as a mighty strongman, personally subduing māras and adversaries and protecting the Buddhas. Now the Buddha asks about the gateway to perfect penetration: through deep and subtle contemplative practice I observed the vital warmth/warmth and touch (of life) on body and mind; the warmth pervaded body and mind, all afflictive outflows were exhausted, and the mind gave rise to a vast flame of wisdom, ascending to unsurpassed enlightenment. This is the foremost gateway to perfect penetration by which I cultivated.

Why can meditative concentration and samādhi subdue and cut off the afflictions of greed and desire? Because meditative concentration can transform body and mind, endowing them with blissful sensation; this bliss is extremely pure and sublime, surpassing the pleasure of sexual lust in the human world—especially the dhyāna of the first dhyāna and the third dhyāna. When a person possesses the more sublime bliss of meditative concentration, they naturally no longer delight in the coarse and crude pleasure of sexual lust. After attaining samādhi, the bliss of body and mind becomes even more sublime and pure, and the lustful mind is transformed into the fire of wisdom. Therefore meditative concentration can subdue afflictions, and samādhi can cut off afflictions; for those seeking liberation, neither of the two can be lacking.