(pneumatike petra): Having a spiritual significance: supernatural, manifesting the power of the Divine Spirit; allegorically applied to Christ as fulfilling the type in the smitten rock in the desert, from which water miraculously burst forth to nourish the Israelites. A tradition current among the Jews affirms that this rock followed the people in their journeyings and gave forth a living stream for their supply. Paul made this ever-flowing rock a beautiful and accurate symbol of Christ: "The rock was Christ" (1Co 10:4).
Without the characterizing word "spiritual," this figurative term, with the same significance, is common to the Scriptures; applied (1) to Yahweh, God: "Rock of his salvation," "their rock is not as our Rock" (De 32:15,31); "Yahweh is my rock" (Ps 18:2; compare Isa 26:4; 32:2; 1Sa 2:2; 2Sa 22:2); (2) to the foundation-stone of Christian confession and testimony (Mt 16:18; compare Eph 2:20; 1Co 3:11; 1Pe 2:6-8), and thus to Christ Himself; (3) in Christian hymnology to Jesus crucified and spear-pierced: "Rock of ages, cleft for me."
Dwight M. Pratt