Shiva Purana
अर्थं तस्यानुसन्धाय पर्वण्यनशनः पठेत् ॥ अष्टाभ्यां वा चतुर्दश्यां फलमर्धं समाप्नुयात् ॥ १०२ ॥
If any one thinks into the hymn, observes fast on the full moon and the new moon days and recites it on those days or on the eighth or fourteenth day, he shall derive half the benefit.
english translation
arthaM tasyAnusandhAya parvaNyanazanaH paThet ॥ aSTAbhyAM vA caturdazyAM phalamardhaM samApnuyAt ॥ 102 ॥
hk transliteration by Sanscript