173 Starting with Origen, various Fathers of the Church reflected on the words of John 7:38 – “out of his heart shall flow rivers of living water” – which refer to those who, having drunk of Christ, put their faith in him. Our union with Christ is meant not only to satisfy our own thirst, but also to make us springs of living water for others. Origen wrote that Christ fulfils his promise by making fountains of fresh water well up within us: “The human soul, made in the image of God, can itself contain and pour forth wells, fountains and rivers”.
Source: Dilexit Nos (Vatican.va)