Devibhagavatapurana 1.5.14

1.5.14

tānuvāca tataḥ śakraḥ kiṃ kartavyaṃ surottamāḥ |
nidrābhaṅgaḥ kathaṃ kāryaścintayantu surottamāḥ ||

Indra then addressed the Devas:--“O best of the Suras! Now what is to be done! How shall we rouse Bhagavân from His sleep? Now think of the means by which this can be effected”. Hearing Indra's words S’ambhu said:-- “O good Devas! Now we must finish our sacrificial work. But if the sleep of Bhagavân be disturbed, He would get angry.” Hearing S’ankara's words, Paramesthî Brahmâ created Vamrî insects (a sort of white ants) so that they might eat up the forepart of the bow that was lying on the ground causing the other end rise up and thus break His sleep. Thus the Deva's purpose will, no doubt, be fulfilled. Thus settling his mind, the eternal Deva Brahmâ ordered the white ants Vamrîs to cut the bow string.