In 1 Cor. 10 Paul refers to Israel’s being saved, revived, and nourished by miracles corresponding to the NT sacraments of baptism and the Lord’s Supper. Paul asserts that Christ’s presence in OT Israel was so real, and the spiritual blessing He bestowed to His people was so closely bound up with the miraculous physical help He gave them, that He could actually be identified with one of the objects He used in mediating His blessing to them — “that Rock was Christ”(v.4).

“Lord’s Supper (Eucharist)” by R. S. Wallace in ISBE, Vol. 3, 165.