Shiva Purana
तस्माच्छुभतरं चैतत्कर्तव्यं हितमीप्सुभिः ॥ शिवरात्रिव्रतन्दिव्यं भुक्ति मुक्तिप्रदं सदा ॥ १०१ ॥
Hence this auspicious Vrata shall be performed by those who wish for beneficence. Śīvarātri Vrata is divine and it always yields worldly pleasures and salvation.
english translation
tasmAcchubhataraM caitatkartavyaM hitamIpsubhiH ॥ zivarAtrivratandivyaM bhukti muktipradaM sadA ॥ 101 ॥
hk transliteration by Sanscript