Deuterocanon

2 Maccabees 1:19

17 Blessed in every way be our God, who has brought judgment on those who have behaved impiously. 18 Since on the twenty-fifth day of Chislev we shall celebrate the purification of the temple, we thought it necessary to notify you, in order that you also may celebrate the festival of booths and the festival of the fire given when Nehemiah, who built the temple and the altar, offered sacrifices. 19 For when our ancestors were being led captive to Persia, the pious priests of that time took some of the fire of the altar and secretly hid it in the hollow of a dry cistern, where they took such precautions that the place was unknown to anyone.

Date: 100-90 B.C.E.
* Dates are based on scholarly estimates

Ambrose On the Duty of the Clergy 3.17

99 For when our fathers were carried away into Persia, certain priests, who then were in the service of Almighty God, secretly buried in the valley the fire taken from the altar of the Lord. There was there an open pit, with no water in it, and not accessible for the wants of the people, in a spot unknown and free from intruders. There they sealed the hidden fire with the sacred mark and in secret. They were not anxious to bury gold or to hide up silver to preserve it for their children, but in their own great peril, thinking of all that was virtuous, they thought the sacred fire ought to be preserved so that impure men might not defile it, nor the blood of the slain extinguish it, nor the heaps of miserable ruins cover it.

Date: 390-395 C.E.
* Dates are based on scholarly estimates