In the book of Daniel it is related that Nebuchadnezzar, king of Babylon (605 BCE), had four Jewish advisors: Daniel, Chananyah, Mishael, and Azariah. The Babylonians, who envied their greatness, decided to bear tales against Chananyah, Mishael, and Azariah to the king (Daniel is not mentioned in this incident), saying that they did not bow before the king’s likeness. The king decided to punish them by throwing them into a furnace; a miracle occurred and they were saved. After the miracle we hear about Daniel and his greatness, but no more of Chananyah, Mishael, and Azariah; we know not what became of them. Chazal were left with two questions from the story related at the start of the book of Daniel:
1.What happened to Chananyah, Mishael, and Azariah after they were saved from the fire?
2. Why didn’t the Babylonians report Daniel or throw him into the furnace? Where was Daniel during the drama which engulfed Chananyah, Mishael, and Azariah?

Where did Chananyah, Mishael, and Azariah go after they were saved from the fiery furnace? Answer: Rav said they died because of the evil eye; the people would look at them in amazement that they were saved and these glances (the evil eye) caused their deaths.
A different sage, Samuel, said that they drowned in the spittle spit by the gentiles on the other Jews, who had worshipped the image. The gentiles said “You have such a god and you bow before an idol?” Another sage, Rabbi Yochanan, explained that the emigrated from Babylon and went to the Land of Israel, where they started families. Chazal also asked where Daniel was when Chananyah, Mishael, and Azariah were thrown into the furnace in Babylon. Answer: Rav said that Daniel had gone to dig a river in Tiberius. Samuel said that Daniel had gone to bring seeds of grain for Nebuchadnezzar. Rabbi Yochanan said that Daniel had gone to fetch prize pigs from Egypt, so that prize Egyptian pigs could be raised in Babylon. The scholars asked: Did not Theodos the doctor (2nd century CE) testify that the Egyptians allowed no sow to leave the country without first removing her womb so they could not be bred and create economic competition in the prize pig market? If so, why did Daniel go to fetch sows with no womb? Answer: Daniel brought piglets. The Egyptians paid the young pigs no mind and so did not remove their wombs.
(Babylonian Talmud, Tractate Sanhedrin 93a)