Long ago, many virtuous seers lived in huts on the seashore. At that time there was a war between the gods and the Asuras. The seers considered the gods righteous but feared harm from the Asuras. They went, therefore, to Sambara, lord of the Asuras, and asked him for a pledge of safety; he refused, saying that the seers were followers of Sakka. The seers thereupon cursed him to suffer everlasting terror. It is said that that same night Sambara woke up thrice, seized with fright (S.i.227-8).
Buddhaghosa (SA.i.266) adds that as a result of this curse, Sambara's mind became deranged and he came to be called Vepacitti (crazy-nerve).