Skanda Purana 16.184

Īśvara said: / Then one should go, O great goddess, to the unsurpassed Maṅkīśvara, / situated near Trisaṅgama, which destroys all sins.

Formerly there was a seer named Maṅkī, the best of those performing austerities. / Having recognized the great field of Prabhāsa, dear to Śaṃkara,

he performed severe austerity, eating only roots, tubers, and fruits, / for fully ten thousand years, having installed Maheśvara.

Then Mahādeva, pleased, granted him a boon at that time. / He chose: "If you are pleased, remain in this place,

abiding as a liṅga marked with my name for tens of thousands of kalpas." / Saying "So be it," he then vanished right there.

From that time onwards, that liṅga became famed as Maṅkīśvara. / In the month of Māgha, on the thirteenth day or the fourteenth day,

he is to be worshipped with the fivefold offerings, and one will attain the desired fruit. / A gift of a cow should certainly be given there by those desiring the full fruit of pilgrimage.

Thus ends the one hundred and eighty-fourth chapter, entitled "Description of the Māhātmya of Maṅkīśvara," in the first [section, named] Prabhāsakṣetramāhātmya, of the seventh [section, named] Prabhāsakhaṇḍa, in the Skandapurāṇa Mahāpurāṇa of eighty-one thousand verses.