Were all baptized unto Moses. — The weight of evidence is in favour of the middle voice for the verb here used; signifying that they all voluntarily had themselves baptised to Moses. Moses was God’s representative under the Law, and so they were baptised unto him in their voluntarily joining with that “Church” of God which marched beneath the shadow of the cloud, and passed through the waters of the sea — as Christians, are baptised unto Jesus Christ, — He being (in a higher sense both in kind and in degree) God’s representative in the New Dispensation.
The “cloud” and the “sea” refer to the cloud that overshadowed the Israelites (Exodus 13:21, and see Numbers 14:14), and the passage through the Red Sea (Exodus 13:22; Numbers 35:8).