Do Not Affront the Divine Rays of Light

Josephus, Jewish War 2.147-149 (on the Essenes, tr. William Whiston):

Moreover, they are stricter than any other of the Jews in resting from their labors on the seventh day; for they not only get their food ready the day before, that they may not be obliged to kindle a fire on that day, but they will not remove any vessel out of its place, nor go to stool thereon. Nay, on other days they dig a small pit, a foot deep, with a paddle (which kind of hatchet is given them when they are first admitted among them); and covering themselves round with their garment, that they may not affront the Divine rays of light, they ease themselves into that pit, after which they put the earth that was dug out again into the pit; and even this they do only in the more lonely places, which they choose out for this purpose; and although this easement of the body be natural, yet it is a rule with them to wash themselves after it, as if it were a defilement to them.