Numbers 4:3

From thirty years old and upward until fifty years old shalt thou number them; all that enter in to perform the service, to do the work in the tabernacle of the congregation. to perform...: Heb. to war the warfare

Not a novice, lest being lifted up with pride he fall into the condemnation of the devil. a novice: or, one newly come to the faith

Their brethren also the Levites were appointed unto all manner of service of the tabernacle of the house of God.

For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;) through God: or, to God

Now in the second year of their coming unto the house of God at Jerusalem, in the second month, began Zerubbabel the son of Shealtiel, and Jeshua the son of Jozadak, and the remnant of their brethren the priests and the Levites, and all they that were come out of the captivity unto Jerusalem; and appointed the Levites, from twenty years old and upward, to set forward the work of the house of the LORD.

And the pattern of all that he had by the spirit, of the courts of the house of the LORD, and of all the chambers round about, of the treasuries of the house of God, and of the treasuries of the dedicated things: of all that...: Heb. of all that was with him Also for the courses of the priests and the Levites, and for all the work of the service of the house of the LORD, and for all the vessels of service in the house of the LORD.

This charge I commit unto thee, son Timothy, according to the prophecies which went before on thee, that thou by them mightest war a good warfare;

And they shall keep his charge, and the charge of the whole congregation before the tabernacle of the congregation, to do the service of the tabernacle. And they shall keep all the instruments of the tabernacle of the congregation, and the charge of the children of Israel, to do the service of the tabernacle.

And in the seventh year Jehoiada strengthened himself, and took the captains of hundreds, Azariah the son of Jeroham, and Ishmael the son of Jehohanan, and Azariah the son of Obed, and Maaseiah the son of Adaiah, and Elishaphat the son of Zichri, into covenant with him. And they went about in Judah, and gathered the Levites out of all the cities of Judah, and the chief of the fathers of Israel, and they came to Jerusalem. And all the congregation made a covenant with the king in the house of God. And he said unto them, Behold, the king's son shall reign, as the LORD hath said of the sons of David. This is the thing that ye shall do; A third part of you entering on the sabbath, of the priests and of the Levites, shall be porters of the doors; doors: Heb. thresholds And a third part shall be at the king's house; and a third part at the gate of the foundation: and all the people shall be in the courts of the house of the LORD. But let none come into the house of the LORD, save the priests, and they that minister of the Levites; they shall go in, for they are holy: but all the people shall keep the watch of the LORD. And the Levites shall compass the king round about, every man with his weapons in his hand; and whosoever else cometh into the house, he shall be put to death: but be ye with the king when he cometh in, and when he goeth out. So the Levites and all Judah did according to all things that Jehoiada the priest had commanded, and took every man his men that were to come in on the sabbath, with them that were to go out on the sabbath: for Jehoiada the priest dismissed not the courses. Moreover Jehoiada the priest delivered to the captains of hundreds spears, and bucklers, and shields, that had been king David's, which were in the house of God. And he set all the people, every man having his weapon in his hand, from the right side of the temple to the left side of the temple, along by the altar and the temple, by the king round about. side: Heb. shoulder temple: Heb. house Then they brought out the king's son, and put upon him the crown, and gave him the testimony, and made him king. And Jehoiada and his sons anointed him, and said, God save the king. God...: Heb. Let the king live

And the seventh year Jehoiada sent and fetched the rulers over hundreds, with the captains and the guard, and brought them to him into the house of the LORD, and made a covenant with them, and took an oath of them in the house of the LORD, and shewed them the king's son. And he commanded them, saying, This is the thing that ye shall do; A third part of you that enter in on the sabbath shall even be keepers of the watch of the king's house; And a third part shall be at the gate of Sur; and a third part at the gate behind the guard: so shall ye keep the watch of the house, that it be not broken down. that...: or, from breaking up And two parts of all you that go forth on the sabbath, even they shall keep the watch of the house of the LORD about the king. parts: or, companies: Heb. hands And ye shall compass the king round about, every man with his weapons in his hand: and he that cometh within the ranges, let him be slain: and be ye with the king as he goeth out and as he cometh in. And the captains over the hundreds did according to all things that Jehoiada the priest commanded: and they took every man his men that were to come in on the sabbath, with them that should go out on the sabbath, and came to Jehoiada the priest. And to the captains over hundreds did the priest give king David's spears and shields, that were in the temple of the LORD. And the guard stood, every man with his weapons in his hand, round about the king, from the right corner of the temple to the left corner of the temple, along by the altar and the temple. corner: Heb. shoulder And he brought forth the king's son, and put the crown upon him, and gave him the testimony; and they made him king, and anointed him; and they clapped their hands, and said, God save the king. God...: Heb. Let the king live

And Joseph was thirty years old when he stood before Pharaoh king of Egypt. And Joseph went out from the presence of Pharaoh, and went throughout all the land of Egypt.

This is a true saying, If a man desire the office of a bishop, he desireth a good work.