Mudgalapurana 4.1.61

4.1.61

madīyavratajā puṇyā tithistvaṃ ca bhaviṣyasi |
vrateṣu tvatsamaṃ naiva dāyakaṃ kutra vartate ||

You shall become the holy lunar day born of my observance;
among observances, there is none anywhere that gives like you.”