1 Corinthians 10 : 1 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; 2 And were all baptized unto Moses in the cloud and in the sea; 3 And did all eat the same spiritual meat; 4 And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ.

Paul begins this chapter reminding these people of how God guided Israel for 40 years in the wilderness with a cloud in the daytime and a pillar of fire at night and how to begin with they passed through the Red Sea and  the ea closed down on the Egyptian army. All this helped the people to see that this made Moses their leader. That they were also all feed everyday by the manna that God provided and all drank from the Rock that provided the water for them which that Rock was Jesus Christ.  the water that was received from the rock was real water but it was spiritual in the sense that it was given through God’s direct intervention.This is intended to mean that the source of supply was Christ and not the rock and so this passage is an impressive affirmation of the preexistence of Jesus Christ.