Saint John Chrysostom teaches us that the rock which Moses struck foreshadows the table that Christ "touches" at the Last Supper. From the table of Christ pours forth life for the People of God:
From the Catecheses by Saint John Chrysostom (Cat. 3, 24-27: SC 50, 165-167)
Christ and Moses
What distinguished the first Moses? Moses, Scripture tells us, was
more gentle than all who dwelt upon the earth. We can rightly say the
same of the new Moses, for there was with him the very Spirit of
gentleness, united to him in his inmost being. In those days Moses
raised his hands to heaven and brought down manna, the bread
of angels; the new Moses raises his hands to heaven and gives us
the food of eternal life. Moses struck the rock and brought forth streams of water; Christ touches his table, strikes the spiritual rock of the new covenant and draws forth the living water of the Spirit. This rock is like a fountain in the midst of Christ’s table, so that on all sides the flocks may draw near to this living spring and refresh themselves in the waters of salvation.
Since this fountain, this source of life, this table surrounds us with untold blessings and fills us with the gifts of the Spirit, let us approach it with sincerity of heart and purity of conscience to receive grace and mercy in our time of need. Grace and mercy be yours from the only-begotten Son, our Lord and Savior Jesus Christ; through him and with him be glory, honor and power to the Father and the life-giving Spirit, now and always and for ever. Amen.