Once dwelling in Savatthi, the Buddha extolled the virtue of charity by way of the popular tale, which narrates the traditional account of the mark of the hare on the moon.
In one of his pervious births the Bodhisatta was born as a hare in Varanasi. He had three friends – a monkey, a jackal and an otter. Together they resolved to practise charity on the Uposatha day (the day of fast), that was to occur on the following day. In the tradition it was believed that one who stood fast in moral practice and alms-giving on that day would earn a great reward.
Next day, the otter brought seven red fishes abandoned on the bank of the Ganga river. The jackal wrongfully pilfered a lizard and a pot of milk-curd from somebody’s house. The monkey brought a bunch of mangoes. All these three were willing to offer their gifts to some beggar as act of charity. But the hare, when browsing the grass, felt that the grass would not be a good item for alms-giving. He, therefore, decided to offer his entire body in charity.
The hare’s resolve disturbed Lord Sakka (Indra), the king of the deva-s. To examine the hare’s virtue he came down on the earth in the guise of an ascetic and accosted the hare for food. The hare was delighted, because this provided him an opportunity to exemplify his highest act of sacrifice, which a mortal could ever perform. So, he asked the ascetic to pile the logs of wood and kindle the fire, where he would jump to offer his roasted meat to the latter.
When Sakka caused the heap of burning coals to appear, the hare shook himself thrice lest there were any insect in his fur. Thus, offering his whole body he fell on the heap of the burning twigs.
The fire, however, did not burn him. Impressed with the act, Sakka revealed his identity and applauded the hare’s virtue. He said `O wise hare! Be thy virtue known through out this whole aeon!” He then by squeezing the mountain daubed the sign of hare on the orb of the moon with its extracted essence.
We thus see the mark of the hare still visible on the moon to tell the saga of the Great Sacrifice.