Devas' Mortality

Deva can die by own angry mind. See Dha.A.2 appamāda-cittavagga Sāmāvatīvatthu (ghosakadevaputta).

A yakkha is a type of deva, that is tree-dwelling. They live in the plane of the Devas of the Four Great Kings (catumaharajika deva).

Udana 4.4 tells the story of a yakkha, who despite being warned by his mate, gave Venerable Sariputta the Arahant, a strong blow to the head. The yakkha immediately fell into the Great Hell.

I have heard that on one occasion the Blessed One was staying near Rājagaha at the Bamboo Grove, the Squirrels' Sanctuary. And on that occasion Ven. Sāriputta and Ven. Mahā Moggallāna were staying in Pigeon Cave. Then, on a moonlit night, Ven. Sāriputta — his head newly shaven — was sitting in the open air, having attained a certain level of concentration.

And on that occasion two yakkhas who were companions were flying from north to south on some business or other. They saw Ven. Sāriputta — his head newly shaven — sitting in the open air. Seeing him, the first yakkha said to the second, "I'm inspired to give this contemplative a blow on the head."

When this was said, the second yakkha said to the first, "Enough of that, my good friend. Don't lay a hand on the contemplative. He's an outstanding contemplative, of great power & great might."

A second time, the first yakkha said to the second, "I'm inspired to give this contemplative a blow on the head."

A second time, the second yakkha said to the first, "Enough of that, my good friend. Don't lay a hand on the contemplative. He's an outstanding contemplative, of great power & great might."

A third time, the first yakkha said to the second, "I'm inspired to give this contemplative a blow on the head."

A third time, the second yakkha said to the first, "Enough of that, my good friend. Don't lay a hand on the contemplative. He's an outstanding contemplative, of great power & great might."

Then the first yakkha, ignoring the second yakkha, gave Ven. Sāriputta a blow on the head. And with that blow he might have knocked over an elephant seven or eight cubits tall, or split a great rocky crag. But right there the yakkha — yelling, "I'm burning!" — fell into the Great Hell.

Now, Ven. Moggallāna — with his divine eye, pure and surpassing the human — saw the yakkha give Ven. Sāriputta a blow on the head. Seeing this, he went to Ven. Sāriputta and, on arrival, said to him, "I hope you are well, friend Sāriputta. I hope you are comfortable. I hope you are feeling no pain."

"I am well, friend Moggallāna. I am comfortable. But I do have a slight headache."

"How amazing, friend Sāriputta! How astounding! How great your power & might! Just now a yakkha gave you a blow on the head. So great was that blow that he might have knocked over an elephant seven or eight cubits tall, or split a great rocky crag. But all you say is this: 'I am well, friend Moggallāna. I am comfortable. But I do have a slight headache'!"

"How amazing, friend Moggallāna! How astounding! How great your power & might! Where you saw a yakkha just now, I didn't even see a dust devil!"

The Blessed One — with the divine ear-property, pure and surpassing the human — heard those two great beings conversing in this way. Then, on realizing the significance of that, the Blessed One on that occasion exclaimed:

Whose mind, standing like rock,
doesn't shake, dispassionate for
things that spark passion,
unprovoked by things that spark provocation:
When one's mind is developed like this,
from where can there come to him
suffering & stress?