“If anyone thirsts, let him come to me and drink. Rivers of living water will brim and spill out of the depths of anyone who believes in me this way, just as the Scripture says.” (The Message)
This is the fruit of Jesus giving His life for us. The resurrection enables us to find our thirsts quenched in Him. The resurrection, the ascension, the giving of the Holy Spirit, and now all who thirst and come to Jesus will overflow.
Many commentators believe that one passage Jesus might be quoting here is Ezekiel 47:1-12. The culmination of that passage is in verse 12, "But the river itself, on both banks, will grow fruit trees of all kinds. Their leaves won’t wither, the fruit won’t fail. Every month they’ll bear fresh fruit because the river from the Sanctuary flows to them. Their fruit will be for food and their leaves for healing.”
Now that's good news.