Saṃyukta Āgama 623 The World Beauty
Thus have I heard. At one time the Buddha was in Vārāṇasī, at the Deer Park in Ṛṣipatana. At that time, the Bhagavān said to the bhikṣus, “Would a lady, said to be the most beautiful in the world, cause many people to gather together to see her?” The bhikṣus replied to the Buddha, “Certainly, Bhagavān.” The Buddha said to the bhikṣus, “If that lady, reputed to be most beautiful in the world, could perform all kinds of music, song, and dance, would many people gather together to watch?” The bhikṣus addressed the Buddha, saying, “Certainly, Bhagavān.”
The Buddha said to the bhikṣus, “Suppose there were a lady said to be the most beautiful in the world, and in this place there would be all kinds of entertainment with music, song, and dance. Moreover, a great crowd would converge upon this one place. Suppose there would be a gentleman, not foolish or stupid, preferring happiness to suffering, valuing life and fearing death. A person would say to him, ‘Sir, you should carry this bowl of oil, filled to the brim, and pass in between this world beauty and the crowd. There is a killer who will draw out his blade and follow you. If a single drop of oil is lost, he will cut off your head.’
“What do you think, bhikṣus? Would that man carrying the oil bowl be able to forget about the oil bowl, and forget about the killer, and watch that skillful lady and the large crowd of people?” The bhikṣus addressed the Buddha, saying, “No, Bhagavān. Why? Bhagavān, that man would be concerned about the man with his blade drawn out. He would think, ‘If I spill even one drop of oil, that man with his blade drawn will cut off my head.’ With that only thought, his mind would be fixated on the oil bowl. He would walk between the world beauty and the crowd and go past them, not daring to catch a glimpse.”
“Thusly, bhikṣus, if there is a śramaṇa or brāhmaṇa who is dignified in body and resolute in mind, not regarding voice and beauty, skillfully regarding all dharmas of the mind, abiding in mindfulness of the body, then this is my disciple who is in accordance with my teaching.
“What does it mean for a bhikṣu to be dignified in body and resolute in mind, not regarding voice and beauty, persevering in all dharmas of the mind, abiding in mindfulness of the body? Thusly, bhikṣus:  mindful of the body, observing the body: ardent, correctly aware and mindful, setting aside worldly craving and sorrow. Abiding in the mindfulness of  sensations; and  of the mind; and  of dharmas, observing dharmas, is also such as this. This is called a bhikṣu who is dignified in body, resolute in mind, not regarding voice and beauty, and skillfully regarding dharmas of the mind, abiding in the Four Bases of Mindfulness.”
At that time, the Bhagavān spoke a gāthā:
Focused and well-mindful, As if protecting an oil bowl: The mind protected this way Reaches the unprecedented— What is extremely difficult to reach, Supremely wondrous and subtle. Those things the Buddha speaks: That teaching is a sharp sword. With a resolute mind, Focusing and persevering— Not like an ordinary person, Negligent in affairs— One is able to enter thusly, Not neglecting the teaching.
After the Buddha had spoken this sūtra, the bhikṣus heard what the Buddha had said, and joyfully practiced in accordance.