You shall take the atonement money from the people of Israel and shall give it for the service of the tent of meeting, that it may bring the people of Israel to remembrance before the LORD, so as to make atonement for your lives.”
Some observe that the repetition of those words, The Lord spoke unto Moses, here and afterwards (Exo 30:17, Exo 30:22, Exo 30:34), intimates that God did not deliver these precepts to Moses in the mount, in a continued discourse, but with many intermissions, giving him time either to write what was said to him or at least to charge his memory with it.
Commenting on Exodus 30:11-16
And thou shall take the atonement money of the children of Israel,.... The half shekel, the ransom of their souls: and shall appoint it for the service of the tabernacle of the congregation; for the building of the tabernacle, for the repairs of it, and for the sacrifices offered in it; particularly we find that this first collection this way was appropriated to the silver...
Exo 30:16 This atonement-money Moses was to appropriate to the work of the sanctuary (cf. Exo 38:25-28, where the amount and appropriation are reported). Through this appropriation it became “a memorial to the children of Israel before the Lord to expiate their souls,” i.e., a permanent reminder of their expiation before the Lord, who would henceforth treat them as reconciled because of this payment.