On the observance day, four or more resident monks may have gathered together in a certain monastery. They don’t know there are other resident monks who haven’t arrived. Perceiving that they’re acting according to the Teaching and the Monastic Law, perceiving that the assembly is complete although it’s not, they do the observance-day ceremony and recite the Monastic Code. When they’ve just finished, and none of the gathering has left, a smaller number of resident monks arrive. In such a case, what has been recited is valid, and the late arrivals should announce their purity in the presence of the others. There’s no offense for the reciters. On the observance day, four or more resident monks may have gathered together in a certain monastery. They don’t know there are other resident monks who haven’t arrived.