And were all baptized - In regard to the meaning of the word "baptized," see the note at Matthew 3:6. We are not to suppose that the rite of baptism, as we understand it, was formally administered by Moses, or by any other person, to the Jews, for there is not the least evidence that any such rite was then known, and the very circumstances here referred to forbid such an interpretation. They were baptized "in the cloud" and "in the sea," and this cannot be understood as a religious rite administered by the hand of man. It is to be remembered that the word "baptism" has two senses - the one referring to the application of water as a religious rite, in whatever mode it is done; and the other the sense of "dedicating, consecrating, initiating into," or bringing under obligation to. And it is evidently in this latter sense that the word is used here, as denoting that they were devoted to Moses as a leader, they were brought under his laws, they became bound to obey him, they were placed under his protection and guidance by the miraculous interposition of God. This was done by the fact that their passing through the sea, and under the cloud, in this manner, brought them under the authority and direction of Moses as a leader, and was a public recognition of their being his followers, and being bound to obey his laws.
Unto Moses - (εἰς eis). This is the same preposition which is used in the form of baptism prescribed in Matthew 28:19. See the note at that place. It means that they were thus devoted or dedicated to Moses; they received and acknowledged him as their ruler and guide; they professed subjection to his laws, and were brought under his authority. They were thus "initiated into" his religion, and thus recognized his divine mission, and bound themselves to obey his injunctions - Bloomfield.
In the cloud - This cannot be proved to mean that they were enveloped and, as it were, "immersed" in the cloud, for there is no evidence that the cloud thus enveloped them, or that they were immersed in it as a person is in water. The whole account in the Old Testament leads us to suppose that the cloud either passed before them as a pillar, or that it had the same form in the rear of their camp, or that it was suspended over them, and was thus the symbol of the divine protection. It would be altogether improbable that the dark cloud would pervade the camp. It would thus embarrass their movements, and there is not the slightest intheation in the Old Testament that it did. Nor is there any probability in the supposition of Dr. Gill and others, that the cloud. as it passed from the rear to the front of the camp, "let down a plentiful rain upon them, whereby they were in such a condition as if they had been all over dipped in water." Because:
(1) There is not the slightest intheation of this in the Old Testament.
(2) The supposition is contrary to the very design of the cloud. It was not a natural cloud, but was a symbol of the divine presence and protection. It was not to give rain on the Israelites, or on the land, but it was to guide, and to be an emblem of the care of God.
(3) it is doing violence to the Scriptures to introduce suppositions in this manner without the slightest authority. It is further to be observed, that this supposition does by no means give any aid to the cause of the Baptist after all. In what conceivable sense were they, even on this supposition, "immersed?" Is it "immersion in water" when one is exposed to a shower of rain? We speak of being "sprinkled or drenched" by rain, but is it not a violation of all propriety of language to say that a man is "immersed" in a shower? If the supposition, therefore, is to be admitted, that rain fell from the cloud as it passed over the Jews, and that this is meant here by "baptism unto Moses," then it would follow that "sprinkling" would be the mode referred to, since this is the only form that has resemblance to a falling shower. But the supposition is not necessary. Nor is it needful to suppose that water was applied to them at all. The thing itself is improbable; and the whole case is met by the simple supposition that the apostle means that they were initiated in this way into the religion of Moses, recognized his divine mission, and under the cloud became his followers and subject to his laws. And if this interpretation is correct, then it follows that the word "baptize" does not of necessity mean to "immerse." (See Editors' Notes on Matthew 3:6 and Matthew 3:16.)
And in the sea - This is another expression that goes to determine the sense of the word "baptize." The sea referred to here is the Red Sea, and the event was the passage through that sea. The fact in the case was, that the Lord caused a strong east wind to blow all night, and made the sea dry land, and the waters were divided Exodus 14:21, and the waters were a wall unto them on the right hand and on the left, Exodus 14:22. From this whole narrative it is evident that they passed through the sea without being "immersed" in it. The waters were driven into high adjacent walls for the very purpose that they might pass between them dry and safe. There is the fullest proof that they were not submerged in the water. Dr. Gill supposes that the water stood up above their heads, and that "they seemed to be immersed in it." This might be true; but this is to give up the idea that the word baptize means always to immerse in water, since it is a fact, according to this supposition, that they were not thus immersed, but only seemed to be. And all that can be meant, therefore, is, that they were in this manner initiated into the religion of Moses, convinced of his divine mission, and brought under subjection to him as their leader, lawgiver, and guide. This passage is a very important one to prove that the word baptism does not necessarily mean entire immersion in water. It is perfectly clear that neither the cloud nor the waters touched them. "They went through the midst of the sea on dry ground." It remains only to be asked whether, if immersion was the only mode of baptism known in the New Testament, the apostle Paul would have used the word not only so as not necessarily to imply that, but as necessarily to mean something else? (See Editors' Notes on Matthew 3:6 and Matthew 3:16.)

And were all baptized unto Moses - Rather Into Moses - into the covenant of which Moses was the mediator; and by this typical baptism they were brought under the obligation of acting according to the Mosaic precepts, as Christians receiving Christian baptism are said to be baptized Into Christ, and are thereby brought under obligation to keep the precepts of the Gospel.

(2) And were all (b) baptized unto (c) Moses in the cloud and in the sea;
(2) In effect the ordinances of the old fathers were all one with ours, for they respected Christ alone, who offered himself to them in different forms.
(b) All of them were baptized with the outward sign, but not indeed, because of which God cannot be blamed, but they themselves.
(c) Moses being their guide.

And were all baptized unto Moses,.... "In or by Moses"; and so the Syriac version renders it, , "by the hand of Moses"; by his means and direction, he going before, they followed after him into the sea, and passed through on dry land, and came out on the shore, which carried in it a resemblance of baptism; when they believed the Lord, and his servant Moses, Exodus 14:31 and gave up themselves to him as their leader and commander through the wilderness: and this their baptism was
in the cloud, and in the sea; which may be considered either as together or separately; if together, the agreement between them and baptism lay in this; the Israelites, when they passed through the Red sea, hid the waters on each side of them, which stood up as a wall higher than they, and the cloud over them, so that they were as persons immersed in and covered with water; and very fitly represented the ordinance of baptism as performed by immersion; and which is the way it was administered in the apostles' time, to which he refers; and is the only way it ought to be administered in; and in which only the Israelites' passage through the sea, and under the cloud, could be a figure of it: or this may be considered separately, they were baptized in the cloud; which was either, as Gataker (g) thinks, when the cloud went from before the face of the Israelites, and stood behind them, and was between the two camps, to keep off the Egyptians from them, which as it passed over them let down a plentiful rain upon them, whereby they were in such a condition as if they had been all over dipped in water; or their being all under the cloud, and all over covered with it, was a representation of the ordinance of baptism, in which a person is all over covered with water; and then they were baptized in the sea, as they passed through it, the waters standing up above their heads, they seemed as if they were immersed in it. Very great is the resemblance between that passage of theirs, and baptism. For instance, their following Moses into the sea, which is meant by their being "baptized into him", was an acknowledgment of their regard unto him, as their guide and governor, as baptism is a following of Christ, who has left us an example that we should tread in his steps; and is an owning him to be our prophet to teach us, and lead us the way; and it is a profession of our faith in him, as our surety and Saviour, and a subjection to him as our King and Governor. This their baptism in the sea was after their coming out of Egypt, and at their first entrance on their journey to Canaan's land, as our baptism is, or should be, after a person is brought out of worse than Egyptian bondage and darkness, and has believed on the Lord Jesus Christ, and at the beginning of his profession of him, and entrance on his Christian race. The descent of the Israelites into the sea, when they seemed as buried in the waters, and their ascent out of it again on the shore, has a very great agreement with baptism, as administered by immersion, in which the person baptized goes down into the water, is buried with Christ therein, and comes up out of it as out of a grave, or as the children of Israel out of the Red sea; and as they, when they came out of it, could rejoice and sing in the view of their salvation and safety, and of the destruction of all their enemies, so the believer can, and does rejoice in this ordinance, in the view of his salvation by Christ, and safety in him, and of all his sins being buried and drowned in the sea of his blood; witness the instances of the eunuch and jailer. But though the Israelites were all in this sense baptized, yet they did not all inherit the land of Canaan.
(g) Aniversar. Miscellan. p. 30.

And--"And so" [BENGEL].
baptized unto Moses--the servant of God and representative of the Old Testament covenant of the law: as Jesus, the Son of God, is of the Gospel covenant (John 1:17; Hebrews 3:5-6). The people were led to believe in Moses as God's servant by the miracle of the cloud protecting them, and by their being conducted under him safely through the Red Sea; therefore they are said to be "baptized unto" him (Exodus 14:31). "Baptized" is here equivalent to "initiated": it is used in accommodation to Paul's argument to the Corinthians; they, it is true, have been "baptized," but so also virtually were the Israelites of old; if the virtual baptism of the latter availed not to save them from the doom of lust, neither will the actual baptism of the former save them. There is a resemblance between the symbols also: for the cloud and sea consist of water, and as these took the Israelites out of sight, and then restored them again to view, so the water does to the baptized [BENGEL]. OLSHAUSEN understands "the cloud" and "the sea" as symbolizing the Spirit and water respectively (John 3:5; Acts 10:44-47). Christ is the pillar cloud that screens us from the heat of God's wrath. Christ as "the light of the world" is our "pillar of fire" to guide us in the darkness of the world. As the rock when smitten sent forth the waters, so Christ, having been once for all smitten, sends forth the waters of the Spirit. As the manna bruised in mills fed Israel, so Christ, when "it pleased the Lord to bruise Him," has become our spiritual food. A strong proof of inspiration is given in this fact, that the historical parts of Scripture, without the consciousness even of the authors, are covert prophecies of the future.

And were all, as it were, baptized unto Moses - initiated into the religion which he taught them. In the cloud and in the sea - Perhaps sprinkled here and there with drops of water from the sea or the cloud, by which baptism might be the more evidently signified.