The Bodhisatta was once a garuda king. A ship full of merchants wrecked in the ocean and only one man survived. He floated to land without anything, even clothes, and went about begging. People assumed he was a naked ascetic and treated him well, giving him plenty of food and building him a small home, so the man chose to actually live as an ascetic. People didn’t know his true nature, so he was widely respected and his followers included the Bodhisatta and a naga king.
One day the Bodhisatta met with the ascetic to discuss a problem. Garuda, he explained, often died when attacking naga because the naga had a secret defense. He asked the ascetic to extract the best method to seize them from the naga king and tell him. The ascetic agreed to try. The next time the naga king came to see him, the ascetic asked how garudas could safely seize nagas. The naga king said it was a secret he would never tell because if the garuda knew, all naga would be killed. The ascetic said he only asked out of his own curiosity and promised to never tell anyone else. The naga was hesitant, but after being asked three times he revealed that naga swallow large stones to make themselves too heavy to lift. If the foolish garudas grabbed them by the tail rather than the head the stones would fall out of their mouths and the naga would be carried away every time. The ascetic promptly shared the secret with the Bodhisatta who immediately flew off to attack his rival.
As he was carried helplessly head-down through the sky, the naga king lamented trusting the wicked ascetic and begged for his life. The Bodhisatta mocked him for sharing a secret with someone and said he got what he deserved for being so foolish. But after lecturing the naga king on the importance of wisdom and caution, the Bodhisatta flew down to the ground and set him free, promising never to attack naga again. But, wanting to test the naga king, the Bodhisatta went to his home and signaled as though he was going to attack. The naga king swallowed up some rocks, coiled up atop his tail, and sat up ready to strike. The Bodhisatta asked why he was afraid, and the naga king answered that he had learned his lesson to not trust anyone. The Bodhisatta appreciated his answer and the two became friends and together went to see the ascetic. Now knowing his true wicked nature, the naga king spoke an Act of Truth (a solemn declaration of one’s supreme virtue followed by a command or request) praying for the ascetic’s destruction and immediately after, the ascetic’s head split into seven pieces and the earth opened up, taking him down to the bottommost hell.
In the Lifetime of the Buddha
The ascetic was an earlier birth of Devadatta, a disciple of the Buddha who became his nemesis and tried to kill him three times. When the Buddha heard some of his disciples discussing how Devadatta had been a liar and was swallowed by the earth into the flames of hell he told them this story so they knew Devadatta had also gone to hell after lying in the past.
The naga king was an earlier birth of Sariputta, one of the Buddha’s top disciples.