Numbers 8:20-26 and John 7:37-39 (New Living Translation)

NUMBERS 8:20-26
THE PURIFICATION AND DEDICATION OF THE LEVITES
20  So Moses, Aaron, and the whole community of Israel dedicated the Levites, carefully following all the Lord’s instructions to Moses.
21  The Levites purified themselves from sin and washed their clothes, and Aaron lifted them up and presented them to the Lord as a special offering. He then offered a sacrifice to purify them and make them right with the Lord.
22  After that the Levites went into the Tabernacle to perform their duties, assisting Aaron and his sons. So they carried out all the commands that the Lord gave Moses concerning the Levites.
23  The Lord also instructed Moses,
24  “This is the rule the Levites must follow: They must begin serving in the Tabernacle at the age of twenty-five,
25  and they must retire at the age of fifty.
26  After retirement they may assist their fellow Levites by serving as guards at the Tabernacle, but they may not officiate in the service. This is how you must assign duties to the Levites.”

JOHN 7:37-39
STREAMS OF LIFE-GIVING WATER
37  On the last day, the climax of the festival, Jesus stood and shouted to the crowds, “Anyone who is thirsty may come to me! 
38  Anyone who believes in me may come and drink! For the Scriptures declare, ‘Rivers of living water will flow from his heart.’”
39  (When he said “living water,” he was speaking of the Spirit, who would be given to everyone believing in him. But the Spirit had not yet been given, because Jesus had not yet entered into his glory.)