154. This is certainly the River proceeding from the throne of God, that is, the Holy Spirit, Whom he drinks who believes in Christ, as He Himself says: “If any man thirst, let him come to Me and drink. He that believeth on Me, as saith the Scripture, out of his belly shall flow rivers of living water. But this spoke He of the Spirit.” S. John vii. 37, 38. Therefore the river is the Spirit.