He should have said it, but he struck it.
God commanded Moses to speak to the rock before the eyes of the Israelites (Num. 20:8).
But Moses lifted up his hand and struck the rock twice with his rod (v. 11).
God said to Moses, “Because you have not believed Me,
To treat Me as holy in the sight of the sons of Israel …” (v. 12).
Nevertheless, God proved Himself holy among them (v. 13).