The Finest Lady in the Land
The Buddha asks the mendicants to imagine a crowd gathering to watch the finest lady in the land dance and sing. A man who wants to live and fears death is told to carry a bowl brimming with oil between the crowd and the performer, followed by a swordsman who will behead him if he spills a drop. Would he let his attention wander? No. The Buddha says he made up the simile to make a point: the bowl full of oil stands for mindfulness of the body. The mendicants should train to develop mindfulness of the body, keep it up, and make it their vehicle and basis.
A note on this text. The simile involves a threat of beheading; the Buddha says explicitly that it is invented to make a point.
The full text
Linked Discourses 47.20 · 2. At Nāḷandā · The Finest Lady in the Land · translated by Bhikkhu Sujato · public domain (CC0) · about 1 min · on SuttaCentral
So I have heard. At one time the Buddha was staying in the land of the Sumbhas, near the town of the Sumbhas named Sedaka. There the Buddha addressed the mendicants, “Mendicants!” “Venerable sir,” they replied. The Buddha said this:
“Mendicants, suppose that on hearing, ‘The finest lady in the land! The finest lady in the land!’ a large crowd would gather. And the finest lady in the land would dance and sing in a most thrilling way. On hearing, ‘The finest lady in the land is dancing and singing! The finest lady in the land is dancing and singing!’ an even larger crowd would gather. Then a person would come along who wants to live and doesn’t want to die, who wants to be happy and recoils from pain. They’d say to him, ‘My man, this is a bowl full to the brim with oil. You must carry it in between this large crowd and the finest lady in the land. And a man with a drawn sword will follow right behind you. Wherever you spill even a drop, he’ll chop off your head right there.’ What do you think, mendicants? Would that person lose focus on that bowl, and negligently get distracted outside?” “No, sir.”
“I’ve made up this simile to make a point. And this is what it means. ‘A bowl of oil filled to the brim’ is a term for mindfulness of the body. So you should train like this: ‘We will develop mindfulness of the body. We’ll cultivate it, make it our vehicle and our basis, keep it up, consolidate it, and properly implement it.’ That’s how you should train.”