Exodus 30:10-12

New Revised Standard Version Catholic Edition

¹⁰ Once a year Aaron shall perform the rite of atonement on its horns. Throughout your generations he shall perform the atonement for it once a year with the blood of the atoning sin offering. It is most holy to the Lord.

The Half Shekel for the Sanctuary

¹¹ The Lord spoke to Moses: ¹² When you take a census of the Israelites to register them, at registration all of them shall give a ransom for their lives to the Lord, so that no plague may come upon them for being registered.