Manava Dharmashastra 11.93

11.93

surā vai malam annānāṃ pāpmā ca malam ucyate
tasmād brāhmaṇarājanyau vaiśyaś ca na surāṃ pibet //

Or, in order to remove (the guilt of) drinking Sura, he may eat during a year once (a day) at night grains (of rice) or oilcake, wearing clothes made of cowhair and his own hair in braids and carrying (a wine cup as) a flag.