The holy priest Copres was an eyewitness of how Saint Patermuthius tended the sick and buried the dead. He also recorded his life and miracles. Saint Copres narrated this Life to the presbyter Rufinus, who in turn transmitted it to Palladius, Bishop of Hellenopolis, who included the account in his book, the LAUSIAC HISTORY.
Once Saint Copres debated with the heretic Manicheus, and seeing that he could not prevail against him in dispute, he suggested that a large fire be lit, and that they should enter it together. In this way, the Lord Himself would decide whose was the true Faith. Manicheus refused to go in first, but Saint Copres went into the fire, and stood in the midst of the flames, yet remained unharmed. The people glorified the faith of Copres, and they threw the heretic into the fire. He jumped out all scorched and tried to flee, but they caught him and again cast him into the flames. Saint Copres then calmed the crowd and released Manicheus.