Numbers 4:43
From thirty years old and upward even unto fifty years old, every one that entereth into the service, for the work in the tabernacle of the congregation, From thirty years old and upward even unto fifty years old, every one that entereth into the service, for the work in the tabernacle of the congregation,
Numbers 4:43 is part of the divine instructions that assigned the Levites to their appointed service in the tabernacle. That service was restricted to a defined period of life, from thirty years old and upward even unto fifty years old. The work embraced by that appointment included erecting and taking down the tabernacle and carrying its sacred furnishings.