Here is, I. An alteration made in the computation of the effective men of the Levites—that whereas, in Moses’s time, they were not enlisted, or taken into service, till they were thirty-years old, nor admitted as probationers till twenty-five (Num. 8:24), David ordered, by direction from God, that they should be numbered for the service of the house of the Lord , from the age of twenty years and u...