Skandapurana 5.211.16

5.211.16

.. śrībhagavānuvāca .. ..
adya śaste dine yo'tra saptamyāṃ ravivāsare ..
sūryodaye naraḥ snānaṃ kariṣyati samāhitaḥ ..
vyādhigrastaḥ sa nīrogastatkṣaṇātsaṃbhaviṣyati .. 16 ..

The Blessed Lord said: / “Whoever today, on this auspicious day, on a Sunday that is a seventh lunar day, / performs ritual ablution with a concentrated mind at sunrise, / even if afflicted with disease, he shall immediately become free from disease.