jn 7:37-39
On the last and greatest day of the feast, Jesus stood up and exclaimed, "Let anyone who thirsts come to me and drink. Whoever believes in me, as scripture says: 'Rivers of living water will flow from within him.'" He said this in reference to the Spirit that those who came to believe in him were to receive. There was, of course, no Spirit yet, because Jesus had not yet been glorified.