Take with thee of the elders of Israel, that they may be eye-witnesses of this glorious work, and may report it to the people. The river; either the Red Sea, for an arm of the sea is sometimes called a river; or the river Nilus.
Related Commentaries of Exodus 17:5
Exodus 17:5
5 And the LORD said unto Moses, Go on before the people, and take with thee of the elders of Israel; and thy rod, wherewith thou smotest the river, take in thine hand, and go.