Ex 17:5

17:5 Pass on before the people. The people want a trial. God, the just Judge, will give them one. Moses is to pass on before the people, taking in his hand his rod, and accompanied by elders of Israel. The rod of God is identified by the sentence of judgment meted out on Egypt: “with which you struck the Nile,” turning it to blood (cf. Is. 30:31, 32). The elders are summoned as representative witnesses (cf. v. 6).