In John 7:38, Jesus says, "Whoever believes in me, as Scripture has said, rivers of living water will flow from within them." This verse is often understood to be a reference to the Old Testament, specifically to passages such as Isaiah 58:11 and Ezekiel 47:1-12, which speak metaphorically of water flowing from the temple, bringing life and healing to the land.
Ezekiel 47:1-12 describes a vision of a river flowing from the temple, bringing life wherever it goes, and Isaiah 58:11 speaks of the Lord satisfying the needs of the afflicted and watering their parched lands, making them like a well-watered garden. These passages are often interpreted symbolically, with the water representing the life-giving presence of God's Spirit. Jesus, in John 7:38, may be drawing on these Old Testament images to illustrate the transformative power of faith in him.