Leviticus 27:25
25 Every valuation shall be according to cthe shekel of the sanctuary: dtwenty gerahs1 shall make a shekel.
Exodus 30:13
13 Each one who is numbered in the census shall give this: half a shekel1 according to the wshekel of the sanctuary (the xshekel is twenty gerahs),2 yhalf a shekel as an offering to the Lord.