Skandapurana 5.270.26

5.270.26

pratyūṣe vaiṣṇavaṃ bhāvi pāpahāri ca vāsaram..
upavāsaḥ prakarttavyo muktvā vṛddhaṃ ca bālakam..
anyathā nigrahiṣyāmi bhojanaṃ yaḥ kariṣyati..26..

“At daybreak will be the Vaiṣṇava day that removes sin. / A fast must be observed, except by the old and the young; / otherwise I shall punish whoever takes food.”