Bekah

The beka is a unit of silver weight equal to half a sanctuary shekel. It surfaces in the tabernacle accounting as the per-head levy paid by every man counted in the census.

Half a Shekel of the Sanctuary

When the silver collected for the tabernacle is tallied, the rate is fixed at "a beka a head, [that is], half a shekel, after the shekel of the sanctuary, for everyone who passed over to those who were numbered, from twenty years old and upward, for six hundred thousand and three thousand and five hundred and fifty men" (Ex 38:26). The bracketed gloss inside the verse defines the beka itself — half a shekel by sanctuary standard — and the totals show how the small per-head unit aggregated into the tabernacle's silver fittings.