What Does Exodus 12:21 Mean?

Then Moses called all the elders of Israel and said to them, "Go and select lambs for yourselves according to your clans, and kill the Passover Lamb." Moses' first action after receiving the Passover instructions is to call the elders of Israel, the community's leadership structure, and give them the order to select and slaughter the Passover lambs.

The elder-based implementation is the first use of Israel's leadership structure in the liberation: the elders receive the command from Moses and transmit it to their clans. The prophetic word flows from YHWH to Moses to the elders to the households; the Passover is a community-wide event organized through the existing social structure.

The "select lambs for yourselves according to your clans" personalizes the Passover at the clan level: each clan has its own selection process, its own set of lambs chosen by its own members. The communal simultaneity of the Passover slaughter does not eliminate the personal engagement each household has with its own specific lamb. The "for yourselves" (lachem) returns the personal language of the earlier instructions: this is your lamb, your protection, your participation in the liberation.

The "kill the Passover lamb" is the first use of the term "Passover lamb" (zevach ha-pesach, the sacrifice of the passing-over) as a name for the ritual's central element. The Passover has now been named: it is the sacrifice of the passing-over, the slaughter through which YHWH's protection passes over the household. The naming at the point of execution, as Moses gives the slaughter order to the elders, gives the event its identity: this killing of an animal is not arbitrary but the specific act that constitutes the Passover sacrifice.