Shiva Purana

siva.sh/siva-purana/rudra-samhita/10/19

वैष्णवेन तु वर्षेण दिनं रौद्रं भवेद्ध्रुवम्।। हरो वर्षशते याते नररूपेण संस्थितः।।१९।।

sanskrit

One year of Viṣṇu constitutes one day of Rudra. When a hundred year period passes, Rudra assumes the form of Nara (supreme Man).

english translation

vaiSNavena tu varSeNa dinaM raudraM bhaveddhruvam|| haro varSazate yAte nararUpeNa saMsthitaH||19||

hk transliteration by Sanscript