These were miracles that were visible to the outer world as well, but there were others that were known to Israel alone. During their forty years' march they had no need of change of raiment. The robe of purple which the angels clothed each one among them at their exodus from Egypt remained ever new; and as a snail's shell grows with it, so did their garments grow with them. Fire could not injure these garments, and though they wore the same things throughout forty years, still they were not annoyed by vermin, yes, even the corpses of this generation were spared by worms.