Matsya Purana 193.22

193.22

daśāśvamedhajananaṃ triṣu lokeṣu viśrutam.
upoṣya rajanīmekāṃ māsi bhādrapade tathā .. 193.21

One who bathes there goes before the Lord Śiva One who bathes and offers libations to the manes on the occasion of each festival, at that sacred place, gets the benefit of Aśwamedha sacrifice The devotee gets all the benefits that accrue at Prayâga as detailed by Śankarâchârya To the west of Gaṅgâvadana is the sacred Daśa śwamedhajanana tirtha which is known in all the three realms. One who observes a fast for a night in the month of Bhâdra and one who bathes there on Amâvâsyâ goes to the realm of Śiva One should bathe there on all festivals.—18-22