What Does Exodus 8:10 Mean?

He said, "Tomorrow." Moses said, "Be it as you say, so that you may know that there is no one like the LORD our God." Pharaoh's answer to Moses' timing offer is "tomorrow." Not "now": tomorrow. The choice of tomorrow rather than immediately has been the subject of significant interpretive discussion: why not "now"?

The most plausible answer is that "tomorrow" gives Pharaoh a way to maintain his interpretive distance: if the frogs left immediately, it might seem too immediate to be attributed to divine power. "Tomorrow" gives him a delay in which the coincidence hypothesis can be maintained. But Moses accepts the tomorrow specification and declares its purpose: "so that you may know that there is no one like the LORD our God."

The knowledge formula "so that you may know that there is no one like the LORD our God" is the plague-purpose statement applied to the Frog removal: not just the frog plague itself but its timed removal will produce the specific knowledge that YHWH is incomparable. "There is no one like the LORD our God" is the incomparability statement that appears in Exodus 15:11 in the Song of Moses: "Who is like you, O LORD, among the gods?" The knowledge that verse 10 says the timed removal will produce is the incomparability knowledge that will be celebrated in the Song of the Sea after the Exodus is complete.

Moses' "be it as you say" is his acceptance of the Pharaoh-specified time. Moses will pray tomorrow, and the frogs will leave tomorrow, because Pharaoh said tomorrow. The acceptance of Pharaoh's timing choice locks in the conditions for the demonstration: Moses' prayer is timed to Pharaoh's request, and the divine response will be timed to Moses' prayer, which was timed to Pharaoh's word. The chain of specification, Pharaoh names the time, Moses prays at that time, YHWH acts at that time, makes the event an undeniable demonstration of YHWH's intercessory responsiveness.