Shiva Purana
ताम्बूलं तैजसम्पात्रं रेतस्सेकं सितांबरम् ॥ दिवास्वापो हि नक्तान्नं यतीनां षड्विवर्जिताः ॥ ३४ ॥
Six things are forbidden to the ascetics: chewing the betel, using the metallic vessel, emission of semen, white cloth, sleeping during the day and taking meal at night.
english translation
tAmbUlaM taijasampAtraM retassekaM sitAMbaram ॥ divAsvApo hi naktAnnaM yatInAM SaDvivarjitAH ॥ 34 ॥
hk transliteration by Sanscript