This valuation was shown to Mosheh in the mountain as with a denarius of fire, and thus spake He to him: So shall every one who passeth to the numberment give a half shekel of the coin of the sanctuary: (a half shekel is twenty manin:) the half shekel is to be the separation before the Lord.
The Denarius of Fire Moses Was Shown on Sinai
Targum Pseudo-Jonathan on Exodus 30:13