Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea; I would not that ye should be ignorant - It seems as if the Corinthians had supposed that their being made partakers of the ordinances of the Gospel, such as baptism and the Lord's Supper, would secure their salvation, notwithstanding they might be found partaking of idolatrous feasts; as long, at least, as they considered an idol to be nothing in the world. To remove this destructive supposition, which would have led them to endless errors both in principle and practice, the apostle shows that the Jews had sacramental ordinances in the wilderness, similar to those of the Christians; and that, notwithstanding they had the typical baptism from the cloud, and the typical eucharist from the paschal lamb, and the manna that came down from heaven, yet, when they joined with idolaters and partook of idolatrous feasts, God was not only displeased with them, but signified this displeasure by pouring out his judgments upon them, so that in one day 23,000 of them were destroyed.
Under the cloud - It is manifest from Scripture that the miraculous cloud in the wilderness performed a three-fold office to the Israelites.
1. It was a cloud in the form of a pillar to direct their journeyings by day.
2. It was a pillar of fire to give light to the camp by night.
3. It was a covering for them during the day, and preserved them from the scorching rays of the sun; and supplied them with a sufficiency of aqueous particles, not only to cool that burning atmosphere, but to give refreshment to themselves and their cattle; and its humidity was so abundant that the apostle here represents the people as thoroughly sprinkled and enveloped in its aqueous vapour. See the note on Exodus 13:21.