King Muchukunda, a king of solar dynasty and son of Mandhata has on the request of god Indra gone to Devaloka along with his forces and defeated the Asuras (demons). Indra wanted to bless him with an award for the service, which he had rendered. Muchukunda, feeling very tired, wanted to be shown a place, where he could have sound sleep, because he had not slept for a long time. Indra led him to a cave on earth and told him that anyone who disturbed him in sleep, would be reduced to ashes by his very look.
Kalayavana went to kili Krishna, but the latter pretended to be in great fear and fled. Kalayavana pursued him, who having come to know about Muchukunda, entered the cave. Kalayavana mistook Muchukunda for Krishna and kicked him violently. Muchukunda jumped up from his sleep and looked at Kalayavana, who was immediately reduced to ashes. Comments : The wicked king got his due punishment.
References :
1. Kohli, Surindar Singh (ed), Dictionary of Mythological References in Guru Granth Sahib, 1993