Charles Ellicott Commentary Exodus 38:21

"This is the sum of [the things for] the tabernacle, even the tabernacle of the testimony, as they were counted, according to the commandment of Moses, for the service of the Levites, by the hand of Ithamar, the son of Aaron the priest." — Exodus 38:21 (ASV)

THE SUM OF THE GOLD, SILVER, AND BRONZE EMPLOYED IN THE TABERNACLE.

This is the sum. —Kalisch translates, “These are the accounts”; Canon Cook, “This is the reckoning.” The expression recurs in Numbers 26:63.

The tabernacle of testimony —i.e., the dwelling which was to contain God’s “testimony” against sin—the Ten Commandments.

For the service of the Levites. —Rather, a service of the Levites: i.e., a service which they rendered “by the hand,” or through the instrumentality of Ithamar. Ithamar was the youngest of the sons of Aaron (Exodus 6:23).