1 Maccabees 6:43

40 Now a part of the king's army was spread out on the high hills, and some troops were on the plain, and they advanced steadily and in good order. 41 All who heard the noise made by their multitude, by the marching of the multitude and the clanking of their arms, trembled, for the army was very large and strong. 42 But Judas and his army advanced to the battle, and six hundred of the king's army fell. 43 Now Eleazar, called Avaran, saw that one of the animals was equipped with royal armor. It was taller than all the others, and he supposed that the king was on it. 44 So he gave his life to save his people and to win for himself an everlasting name. 45 He courageously ran into the midst of the phalanx to reach it; he killed men right and left, and they parted before him on both sides. 46 He got under the elephant, stabbed it from beneath, and killed it; but it fell to the ground upon him and he died. 47 When the Jews saw the royal might and the fierce attack of the forces, they turned away in flight. 48 The soldiers of the king's army went up to Jerusalem against them, and the king encamped in Judea and at Mount Zion.

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

Ambrose On the Duty of the Clergy 1.198

198 Mark the courage of the leader, Judas Maccabæus, as exemplified in the character of one of his soldiers. Eleazar, meeting with an elephant higher than all the rest, and with all the royal trappings upon it, and thinking that the king was on it, ran hastily and threw himself into the midst of the legion; and, casting away his shield, with both hands he slew those opposed to him until he reached the beast. Then he got beneath it, thrust in his sword and slew it. But the beast in falling crushed Eleazar and so killed him. What courage of mind was his then, first, in that he feared not death, next because, when surrounded by enemies, he was carried by it into the thickest of his foes and penetrated the very centre! Then, despising death, and casting away his shield, he ran beneath the huge beast, wounded it with both his hands, and let it fall upon him. He ran beneath it so as to give a more deadly blow. Enclosed by its fall, rather than crushed, he was buried in his own triumph.

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