That spiritual Rock that followed them. — There was a Jewish tradition that the Rock — i.e., a fragment broken off from the rock smitten by Moses — followed the Israelites through their journey, and St. Paul, for the purpose of illustration, adopts that account instead of the statement in Numbers 20:11. The emphatic repetition of the word “spiritual” before “drink” and “rock” reminds the reader that it is the spiritual and not the historic aspect of the fact which is present to St. Paul’s mind. The traditional account of the Rock was a more complete illustration of the abiding presence of God, which was the point that the Apostle here desires to bring forward.
And that Rock was Christ. — As Christ was “God manifest in the flesh” in the New Dispensation, so God manifest in the Rock (the source of sustaining life) was the Christ of the Old Dispensation. The Jews had become familiar with the thought of God as a Rock. (See 1 Samuel 2:2; Psalms 91:12; Isaiah 32:2.) Though the Jews may have recognised the Rock poetically as God, they knew not that it was, as a manifestation of God’s presence, typical of the manifestation which was yet to be given in the Incarnation. Such seems to be the force of the statement and of the word “But” which emphatically introduces it. But though they thought it only a Rock, or applied the word poetically to Jehovah, that Rock was Christ.