This is one of Paul’s best known types or patterns of Christ from the Old Testament:
For I do not want you to be unaware, brethren, that our fathers were all under the cloud and all passed through the sea; 2 and all were baptized into Moses in the cloud and in the sea; 3 and all ate the same spiritual food; 4 and all drank the same spiritual drink, for they were drinking from a spiritual rock which followed them; and the rock was Christ. 5 Nevertheless, with most of them God was not well-pleased; for they were laid low in the wilderness. (1 Corinthians 10:1-5 NASB)
The preexistence of Christ?
It sometimes get raised by Trinitarian, Oneness or Arian (Jehovah’s Witnesses and Russellite) Christians as a proof of the pre-existence of Jesus, some of whom argue that verse 4 shows that Jesus literally followed the Israelites in the wilderness. This is somewhat different from the more common practice of those who believe that Jesus existed before birth hunting for so-called ‘Christophanies’ in the Old Testament, because rather than attempt to identify an angel manifesting God as a pre-birth appearance of Jesus, in this case the the subject is a rock, not an angel, and the rock is actually named and identified as Christ by Paul.
This very obviously allegorical element itself should be enough to make clear that Paul is not literally saying that Christ was a rock. Nor is Paul saying that Christ existed as a rock in the wilderness before his conception in the womb of Mary. Remember that at this time Mary’s (and Christ’s) ancestor Salmon who married Rahab of Jericho was also among the Israelites in the wilderness and among those being followed by the rock, and the descent of Jesus from these ancestors (physically through Mary, legally by adoption by his stepfather Joseph) places Jesus as the fulfilment of the promises of a seed or offspring given in turn to Eve (Genesis 3:15), Abraham (Genesis 22:18), and David (2 Samuel 7:12).
Did the rock move?
It appears that on several occasions the Israelites were provided with miraculous opening of springs in the wilderness. Although only two particularly significant events are recorded in Exodus 17:1-7 and Numbers 20:1-13. A comparison of the two passages show that they occurred in two different regions and two different times.
So the solution here is not to be found in too literal adherence to the events of the Exodus and forty years in the wilderness. Paul is simply using the two water allegories – first baptism in the Red Sea, then secondly the water(s) from the rock(s) to represent the water of life that continues after baptism. Readers sometimes think of the water of life or living water being entirely and idea found in Gospel of John, but this passages shows that Paul also saw this living water as continuing after baptism in the lives in Christ of the Corinthians.