Shiva Purana

siva.sh/siva-purana/saturda-samhita/6/19

अथ तस्यैवमनिशन्तत्परस्य द्विजस्त वै ।। दिव्यम्वर्षसहस्रं तु गतं क्षणमिवाद्भुतम् ।। १९।।

sanskrit

As the brahmin was engrossed in penance day and night, a thousand divine years elapsed like a moment.

english translation

atha tasyaivamanizantatparasya dvijasta vai || divyamvarSasahasraM tu gataM kSaNamivAdbhutam || 19||

hk transliteration by Sanscript