a beka a head (that is, half a shekel, by the shekel of the sanctuary), for everyone who was listed in the records, from twenty years old and upward, for 603,550 men.
Here we have a breviat of the account which, by Moses's appointment, the Levites took and kept of the gold, silver, and brass, that was brought in for the tabernacle's use, and how it was employed. Ithamar the son of Aaron was appointed to draw up this account, and was thus by less services trained up and fitted for greater, Exo 38:21.
Commenting on Exodus 38:21-31
And of the thousand seven hundred seventy five shekels,.... Which remained of the sum collected, Exo 38:25 after the silver sockets were cast: he made hooks for the pillars: on each side of the court of the tabernacle on which the hangings were hung; these hooks, as Kimchi says (t), were in the form of the letter and were made to hang the sacrifices upon...
A bekah for every man - The Hebrew word בקי beka, from בקי baka, to divide, separate into two, seems to signify, not a particular coin, but a shekel broken or cut in two; so, anciently, our farthing was a penny divided in the midst and then subdivided, so that each division contained the fourth part of the penny; hence its name fourthing or fourthling, since corrupted into farthing.