Numbers 18:21

18:21 See, I have given the Levites all the tithes in Israel for an inheritance, for their service which they perform – the service of the tent of meeting.

Numbers 18:31

18:31 And you may ¹  eat it in any place, you and your household, because it is your wages for your service in the tent of meeting.

[18:31]  ¹ tn The verb is the perfect tense with vav (ו) consecutive; it functions as the equivalent of the imperfect of permission.