Manusmriti

siva.sh/manusmriti/4/114

अमावास्या गुरुं हन्ति शिष्यं हन्ति चतुर्दशी । ब्रह्माष्टकपौर्णमास्यौ तस्मात् ताः परिवर्जयेत् ॥ ११४ ॥

sanskrit

The new-moon day destroys the teacher, the fourteenth (day) the pupil, the eighth and the full-moon days (destroy all remembrance of) the Veda; let him therefore avoid (reading on) those (days).

english translation

amAvAsyA guruM hanti ziSyaM hanti caturdazI | brahmASTakapaurNamAsyau tasmAt tAH parivarjayet || 114 ||

hk transliteration by Sanscript