Yet they were not sprinkled or poured either where they, it seems to be that you are taking an idiomatic use of a term to refute it's plain sense meaning. According to T J Conant (The meaning and use of Baptizein, Wakeman Trust) all the greek words for baptism used in classical greek literature always and exclusively mean immerse.
The passage does not say that the Children of Israel didn't get sprinkled. Paul says they were baptized (under the cloud . . . through the sea). He said it. Not me. I know who were immersed, though, and t'weren't the Israelites.

Nevertherless, such is
neither here nor there, since it doesn't change the meaning of
baptizo in my referenced passage. The inspired Apostle calls whatever happened to the children of Israel
baptism, and I'm happy with that against all extra-biblical Greek literature, because I believe we define Scriptural words from their context within
Scripture.
I agree with Jonathan.
I would submit that on a strictly linguistic level there is no apparent reason not to preserve the normal meaning of
baptizo in 1 Corinthians 10:2, especially in light of the descriptive terms that are directly linked to it (e.g. “
passed through the sea” - which is of course derived from the original account in Exodus 14 where phrases like “
the people of Israel went into the midst of the sea” and “
the waters being a wall to them on their right hand and on their left” are used). While being baptized “
into Moses” certainly has an essential spiritual/ecclesial aspect to it (cf. Exodus 14:31; 1 Corinthians 10:3b–4), the historical understanding has been that a generalized state of being “surrounded” by water is almost certainly a practical point of comparison in Paul’s chosen terminology. The immediately paired phrase “
in [
en]
the cloud and [
en]
in the sea” is semantically supportive of such a reading.
If one accepts the conventional view that Paul’s reference to “baptism” here serves partly in an analogous capacity—especially with respect to its literary formulation—then an appropriate point of inquiry is to try and determine what the Egyptians, in relation to how water baptism is portrayed in the New Testament, most reasonably represents in this passage. The seemingly obvious association in such regard would be that the Egyptians were the Israelites’ slave masters (representative of sin and the world), from whom deliverance was desperately needed. That this was indeed one of God’s chief purposes in orchestrating the Exodus is frequently emphasized throughout the Old Testament. For instance—and just shortly after the historical Red Sea crossing—the Ten Commandments were premised with the statement, “
I am the Lord your God, who brought you out of the land of Egypt, out of the house of slavery.” (Exodus 20:2; cf. Exodus 13:3, 14; Deuteronomy 6:12, 7:8, et al)
Direct complimentary support for this interpretation is found elsewhere in Paul’s writings about baptism, where he so poignantly connected being “
baptized” with the “
death...[of]...
the body of sin” to which God’s people were formerly “
enslaved” (Romans 6:3–7). Importantly, this thought sequence occurs in a passage that has historically (indeed, until rather recently, nearly universally) been understood as alluding both to the ancient practice and the symbolical design of baptism by immersion. The fact that the Old Testament alludes to Israel’s Red Sea experience in the exultation that, “
You [God]
will cast all our sins into the depths of the sea” (Micah 7:19b; cf. 6:4, 7:15), also neatly dovetails with this comprehension.
With all this in mind, even the sometimes triumphantly made point that it was the Egyptians who received the ultimate “immersion” in this baptismal event becomes wonderfully meaningful, and makes perfect theological sense. Indeed, this specific typological association used to be enthusiastically championed by many Reformed leaders, including Calvin, Bullinger, Diodati, Ursinus, Gataker, Turretin and Witsius. (What’s happened that’s changed this so radically?!)
The most direct biblical evidence offered by proponents of the relatively recent theory that Paul was alluding to a literal sprinkling or pouring that occurred during the sea crossing, is a lyrical account of the exodus given in Psalms 77, specifically verse 17, which reads, “
The clouds poured out water, the skies sent out a sound.” However, this proposition is inconsistent with the psalmist’s indication that the event he had in view included a violent storm which emanated from “[natural]
clouds” (Hebrew
abot [common plural]), while Paul’s point is clearly that the Israelites were baptized “
in the [supernatural]
cloud” (Greek
nephele [singular]; cf. Exodus 13:21f [
anan—“cloud” singular], 14:19f). And to really be consistent, those who might relish pointing out that it was the Egyptians who were ultimately immersed in the Red Sea must surely acknowledge that this pouring out of water was part of the larger judgment program which was visited on that very same party.
Similarly, if one holds out the literalistic notion that the Israelites were physically sprinkled by their interaction with the sea itself, then it would stand to reason that the surrounding terrain would have been wetted by the same natural process—which is contrary to the explicit statement that the people traversed the sea on dry ground. It is also counter-intuitive to Moses’ wonderment at how the sea had been miraculously “
congealed” (Hebrew qapha—solidify; stiffen), in Exodus 15:8.
It is important to remember that the second NT context where all agree the term “baptism” is used figuratively—namely with respect to the incomprehensibly intense tribulation of Jesus’ Passion (Mark 10:37–40; Luke 12:50)—will bear no other meaning than the classical sense of being “immersed in,” “plunged into,” or “surrounded by” the overwhelming sufferings which He had to endure. In fact, Jesus himself gave this interpretation using other words in a parallel account when He said, “‘
My soul is overwhelmed with sorrow [
perilupos—a compound adjective derived from
peri—encompass; surround—and
lupē—sorrow; grief]
to the point of death.’” (Matthew 26:38)
Still, writings on this topic produced since the 19th century seem to more or less fall out along sectarian lines, with non-immersionists usually insisting there can be no practical relationship between immersion in NT baptism and the typological baptism in 1 Corinthians 10, and immersionists defending the traditional understanding that there is.
Then you'd make a good "immersion only" paedobaptist, Dear Friend, since they all passed through.
I’ve seen this basic argument increasingly advanced in paedobaptist writings. However, I find it difficult from a covenantal perspective to see how the term “baptism” in 1 Corinthians 10 can be compared to NT water baptism in such a directly sacramental way, since the OT corollary to water baptism is always said to be the rite of circumcision. So in the proposed a scheme of things, the Red Sea experience would have to be seen as constituting a “second” baptism of sorts, which would be contra the principles outlined in WCF 27.5 and 28:7. Therefore, the historical symbolic-literary interpretation outlined above seems much more tenable to me.
What about Mark 7:4? καὶ ἀπ' ἀγορᾶς ἐὰν μὴ βαπτίσωνται οὐκ ἐσθίουσιν, καὶ ἄλλα πολλά ἐστιν ἃ παρέλαβον κρατεῖν, βαπτισμοὺς ποτηρίων καὶ ξεστῶν καὶ χαλκίων καὶ κλινῶν -- the καὶ κλινῶν "and couches" is not found in most modern translations, but is supported and should have a higher rating. So, did they immerse their couches? Further, as a point of theology, the inclusion of "dining couches" should serve to draw attention to the fact that a Jewish "baptism" of such items was a purification rite observed by sprinkling (not by immersing) the item to be purified.
This modern incredulity is the result of an anachronistic reading of the text. The
baptismous of cups, pots and copper/brass vessels in Mark 7:4 is undoubtedly connected to the command in Leviticus 11:32 (cf. Leviticus 6:28; Numbers 31:20–23) that when such items became contaminated they were to be cleansed by putting them “
into water [
bo—come/go; put »
b-mayim—in water <> LXX:
bapsesetai (
bapto)
eis hydor].”
Leviticus 15:3–4 and 19–20 also shows that there were circumstances in which beds and sitting implements could likewise be rendered ceremonially unclean. While the remedial process for restoring these articles to a usable state isn’t specified there, the unanimous Jewish interpretation (based on a deductive hermeneutic process called
middot) was that they were to undergo the same remedial procedure prescribed for other inanimate objects, namely the previously mentioned immersion in water. The Mishnah—as well as the archeological discovery of numerous of the immersion pools it directly references in this connection—makes clear that such was indeed the practice in Second Temple Judaism. Here are two relevant instructions from the Mishnah (as paraphrased by Maimonides; re. Miqvaot 7.7f; Kelim 19.1f, et al):
Any object fit for use as a couch or seat, even though it is clean for hallowed things, still in whatever concerns the rite of purification, counts as something which a man with flux has pressed against, unless it is immersed especially for the rite of purification.
...If an object is made of jointed work, having its boards and beams bound together, such as a bed or the like, and it becomes unclean and needs immersion for heave offering, the whole of it may be immersed forthwith while still bound together. But if it is for hallowed things, it must first be unbound and wiped, lest there be anything that interposes, and then it must be immersed and afterward rebound. (H. Danby, The Code of Maimonides; Book Ten, 136, 297)
Regardless of whatever qualms one may have with the traditional Jewish handling of this matter (it is termed a pervasive “tradition” by Mark), simply in terms of word usage it is evident that
baptismous once again retains its normal meaning even in the perhaps unexpected context of Mark 7:4.