Matsya Purana 80.15

80.15

yāvatsamāḥ sapta naraḥ karoti yaḥ saptamīṃ saptavidhānayuktām.
sa saptalokādhipatiḥ krameṇa bhūtvā padaṃ yāti paraṃ murāre.. 80.14 ..

One who keeps up this Saptamî vrata (ordinance), of sevenfold prescription, for a period of seven years, becomes the Lord of seven regions, turn by turn, after which he goes to the region of Viṣṇu and attains bliss there.—14.