Atri Smriti 5.24

5.24

apeyaṃ tadbhavedāpaḥ pītvā cāndrāyaṇaṃ caret
anuvaṃśantu bhuñjīta nānuvaṃśantu saṃviśet

that water becomes undrinkable; having drunk it, one must perform the lunar penance; / one should eat along the line of the house-beam, but one should not sleep along the line of the house-beam;