The Parasite Tychiades (59)

Furthermore, it is no disgrace to him to be the rich man’s parasite, as you imply, evidently assuming that he is the inferior and the other a superior; since surely it is profitable for the rich man to support the parasite, seeing that, besides having him as an ornament, he derives great security from his service as bodyguard. In battle nobody would readily attack the rich man while he saw the other standing by, and in fact no one could die by poison who had a_ parasite; for who would dare to make an attempt on a man when a parasite tastes his meat and drink first? So the rich man not only is ornamented but is actually saved from the greatest: perils by the parasite, who faces every danger on account of his affection, and will not suffer the rich man to eat alone, but chooses even to die from eating with him.