from a moneth] They were numbred in their childhood, because they were chosen for the first-born; but not untill they were a moneth old, for then were they first purged from the impuritie of their birth, Leviticus 12:4. and so the sitter to be dedicated to the Sanctuary; but they began not their service untill they were twentie five yeares old, Numbers 8:24. and from thirtie to fiftie, they were to beare the burdens of the Tabernacle, Numbers 4:3. but in Davids time, and afterward they were to begin their service of the Tabernacle at twentie yeares old, 1 Chron. 23. 24. Ezra 3:8. but then either they were trained up untill twentie five, and then first trusted with any charge; or the searcitie of the ancient men, or forwardnesse of the younger, might bring them the sooner to that service.