One of the fathers used to say that some old men were sitting one day and talking of what was useful to the soul. One of them had the gift of vision, and he saw angels who were waving branches in honor of the old men, but when one of them began to speak of irrelevant things the angels withdrew, and some pigs walked amongst the old men bringing a bad smell and messing up everything. As soon as they began once again to speak of what was useful to the soul, the angels returned to do them honor.