Shiva Purana
दिनमेतत्ततः पुण्यं भविष्यति महत्तरम् । शिवरात्रिरिति ख्याता तिथिरेषा मम प्रिया 1-9-१० ।
Henceforth this day will be famous as “Śivarātri” the holiest of holy days pleasing to me.
english translation
dinametattataH puNyaM bhaviSyati mahattaram । zivarAtririti khyAtA tithireSA mama priyA 1-9-10 ।
hk transliteration by Sanscript