四分律比丘戒本 1.p106

1.p106

If a monk absent himself from the common meal of the monks, except on special occasions, it is pācittiya. The special occasions are, in time of sickness, when the cloth for robes is presented, and when the robes are being made; also, when on a journey or voyage, at the time of a great assembly, or, finally, when a general invitation is given to the ascetics. This is the Rule.