från Eusebius (260-339) "Martyrs of Palestine":
When brought before the tyrant, being very bold in his presence, they were immediately thrown into prison. On the next day, which was the nineteenth of the month Peritius, according to the Roman reckoning the fourteenth before the Kalends of March, they were brought, according to command, before the judge, with Pamphilus and his associates whom we have mentioned. First, by all kinds of torture, through the invention of strange and various machines, he tested the invincible constancy of the Egyptians. Having practised these cruelties upon the leader of all, he asked him first who he was. He heard in reply the name of some prophet instead of his proper name. For it was their custom, in place of the names of idols given them by their fathers, if they had such, to take other names; so that you would hear them calling themselves Elijah or Jeremiah or Isaiah or Samuel or Daniel, thus showing themselves inwardly true Jews, and the genuine Israel of God, not only in deeds, but in the names which they bore. When Firmilianus had heard some such name from the martyr, and did not understand the force of the word, he asked next the name of his country. But he gave a second answer similar to the former, saying that Jerusalem was his country, meaning that of which Paul says, "Jerusalem which is above is free, which is our mother," and, "Ye are come unto Mount Sion, and unto the city of the living God, the heavenly Jerusalem."