I have heard that on one occasion the Blessed One was staying near Sāvatthī at Jeta's Grove, Anāthapiṇḍika's monastery. And on that occasion the young wife of a certain wanderer was pregnant and on the verge of delivery. So she said to the wanderer, "Go, brahman, get some oil for my delivery."
When this was said, the wanderer said to her, "But where can I get any oil?"
A second time, she said to him, "Go, brahman, get some oil for my delivery."
A second time, he said to her, "But where can I get any oil?"
A third time, she said to him, "Go, brahman get some oil for my delivery."
Now on that occasion at the storehouse of King Pasenadi Kosala contemplatives & brahmans were being given as much oil or ghee as they needed to drink, but not to take away. So the thought occurred to the wanderer, "At present at the storehouse of King Pasenadi Kosala contemplatives & brahmans are being given as much oil or ghee as they need to drink, but not to take away. Suppose, having gone there, I were to drink as much oil as I need and, on returning home, vomiting it up, were to give it to use at this delivery?"
So, having gone to the storehouse of King Pasenadi Kosala, he drank as much oil as he needed but, on returning home, was unable to bring it up or pass it down. So he rolled back & forth, suffering from fierce pains, sharp & severe. Then early in the morning the Blessed One adjusted his under robe and — carrying his bowl & robes — went into Sāvatthī for alms. He saw the wanderer rolling back & forth, suffering from fierce pains, sharp & severe.
Then, on realizing the significance of that, the Blessed One on that occasion exclaimed: