The cave is named in the Nilamata Purana and in Kalhana's Rajatarangini, but neither text's date of composition is settled, so their references cannot fix how far back the site's veneration actually runs.
What would resolve this A codicological or paleographic dating study of the manuscript traditions of the Nilamata Purana and the Rajatarangini, or an independently dated inscription or record naming the cave before the nineteenth century.
OpenIndology, manuscript studies, Sanskrit philologyDenise Cush, Catherine Robinson and Michael York (eds.), Encyclopedia of Hinduism