Numbers 31:30

31:30 From the Israelites’ half-share you are to take one portion out of fifty of the people, the cattle, the donkeys, and the sheep – from every kind of animal – and you are to give them to the Levites, who are responsible for the care of the Lord’s tabernacle.”

Numbers 31:47

31:47 From the Israelites’ share Moses took one of every fifty people and animals and gave them to the Levites who were responsible for the care of the Lord’s tabernacle, just as the Lord commanded Moses.

Numbers 18:26

18:26 “You are to speak to the Levites, and you must tell them, ‘When you receive from the Israelites the tithe that I have given you from them as your inheritance, then you are to offer up ¹  from it as a raised offering to the Lord a tenth of the tithe.

[18:26]  ¹ tn The verb in this clause is the Hiphil perfect with a vav (ו) consecutive; it has the same force as an imperfect of instruction: “when…then you are to offer up.”