OT.filter - rotherham performing:

rotherham@Numbers:8:11 @ and Aaron shall offer the Levites as a wave-offering before Yahweh, from among the sons of Israel, so shall they be for performing the laborious work of Yahweh.

rotherham@Numbers:18:21 @ And unto the sons of Levi, lo! I have given all the tenth in Israel for an inheritance, the allotted portion for their laborious work which, they are performing, the laborious work of the tent of meeting: