Why is Jesus called “the Rock”?

Moses asked for many things from His God. He did not desire only the gifts God can give, but went further, asking boldly, “Please show me Your glory” (Ex. 33:18). The Lord answered him, “You cannot see my face, for no man shall see Me and live” (Ex. 33:20). Finally, the Lord appeased Moses by saying, “Here is a place by Me, and you shall stand on the rock. So, it shall be, while My glory passes by, that I will put you in the cleft of the rock , and I will cover you with my hand while I pass by. Then I will take away My hand, and you shall see my back; but my face shall not be seen” (Ex. 33:21–23).

According to St. Ambrose , this conversation points to the divine incarnation.⁷⁶² When God says, “Here is a place by Me,” He means, “I have fulfilled your request as far as you can endure it, for I have borne you to the mystery of the incarnation; so stand on the Rock — which means, be planted upon the Lord Christ, the true Rock. As for His saying, “you shall see My back,” this points to the fullness of time when God overcame the world, declaring His love, when we saw God through His divine incarnation, like one who is covered by the hands of God (Christ), and saw the glory of His divinity from the cleft of a rock. Now we can say with the apostle John , “And we beheld His glory, the glory as of the only begotten of the Father” (John 1:14).

St. Jerome comments on Jesus’ parable about building on the rock or on the sand (Matt 7:24–27), saying, “This rain that tries to undermine the house is the devil. The rivers are all the antichrists, who think contrary to Christ. The winds are the spiritual wickedness in the heavenly places (cf. Eph. 6:3). “And it did not fall; for it had been founded on the rock” (Matt. 7:25). Upon this rock the Lord founded the Church; from this rock also the apostle Peter was allotted his name (cf. Matt. 16:18). The tracks of the serpent are not found upon a rock of this sort (cf. Prov. 30:19). The prophet also speaks confidently about this rock: ‘He has established my feet upon the rock’ (Ps. 40:2), and in another place: ‘The rock is a refuge for’ hares, or ‘badgers’ (Ps. 104:18). For a timid animal finds refuge in the crevices of a rock … Moses, at the time when he had fled from Egypt and was a little hare of the Lord: ‘Stand in the crevice of the rock, and you will see my back parts.’ (Ex. 33:22–23).”⁷⁶³