In Numbers 4:3 it says that the sons of Levi who were to serve in the Tabernacle were from 30 years old to 50; but in 8:24, it states the age is from 25 to 50. Please explain this contradiction.

In Numbers 4:3, the age of the men was specifically fixed at 30 as being of full maturity to perform the laborious duties as well as the mental acuity required to assist in the management of the sacred services. Numbers 8:24, which states that the age to start their services at 25, seems to contradict 4:3 which states the age as 30. As one studies the Rabbinical writings and Jewish History, we find that they entered into their work or responsibilities in their 25th year. For 5 years they were in their apprenticeship, until the age of 30. During their apprenticeship they were occasionally allowed to do the services; but, at the age of 30, they were in full-time service until the age of 50. There is no contradiction at all. From age 25 to 30 they were being trained as pupils and probationers, under the guidance and direction of their senior brothers. At 30, they were admitted to the full discharge of their official duties.