Numbers 8:25 (BSB)

But at the age of fifty, they must retire from performing the work and no longer serve.

From Numbers 8. Also in the ESV.

Commentary on Numbers 8:25

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Numbers 8:5-26: We read before of the separating of the Levites from among the children of Israel when they were numbered, and the numbering of them by themselves (Num 3:6, Num 3:15), that they might be employed in the service of the tabernacle. Now here we have directions given for their solemn ordination (Num 8:6), and the performance of it, Num 8:20.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Numbers 8:25: But shall minister with their brethren in the tabernacle of the congregation,.... By giving advice, instructing younger Levites, and doing lighter service. Jarchi says, they shall return to shutting of doors, singing and loading wagons; but the last especially seems too burdensome: the ministry of such is explained by the next clause: to keep the charge; of the tabernacle, to watch and observe that no...
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on Numbers 8:25: from the age of fifty years they shall cease waiting upon the service thereof, &c.--that is, on the laborious and exhausting parts of their work.
• Geneva Bible Notes (Reformed), Geneva Bible Study Notes on Numbers 8:25: And from the age of fifty years they shall cease waiting upon the service [thereof], and shall serve no more: (k) Such office as was painful, as to bear burdens and such like.