Chronicles II 25:5

5 And Amasias assembled the house of Juda, and appointed them according to the houses of their families for captains of thousands and captains of hundreds in all Juda and Jerusalem: and he numbered them from twenty years old and upwards, and found them three hundred thousand able to go out to war, holding spear and shield.

Chronicles II 25:5 Meaning and Commentary

2 Chronicles 25:5

Moreover Amaziah gathered Judah together
The inhabitants thereof:

and made them captains over thousands, and captains over hundreds,
according to the houses of their fathers, throughout all Judah and
Benjamin;
he divided the people, according to their families throughout his kingdom, into thousands and hundreds, and out of their respective families appointed captains over them:

and he numbered them from twenty years old and above;
the usual age men were numbered at for war, to the fiftieth, according to Josephus; the Roman law F1 obliged none to be soldiers after fifty, nor might any be dismissed before F2; the age of military men with the Romans was from seventeen to forty six, or, as some, forty five; but with the Persians from twenty as here to fifty F3:

and found them three hundred thousand choice men, able to go forth to
war, that could handle spear and shield;
which shows that their number was greatly decreased since the times of Jehoshaphat, ( 2 Chronicles 17:14-18 ) , occasioned by the wars under Jehoram, Ahaziah, and Joash; some copies of the Vulgate Latin F4 have only 30,000.


FOOTNOTES:

F1 Seneca de Brevitate Vitae, c. 20.
F2 Liv. Hist. l. 42. c. 33.
F3 Alex. ab. Alex. Genial. Dier. l. 1. c. 20.
F4 Ed. of Sixtus V. the Lovain and MSS. in James's Corruption of the Fathers, p. 295.

Chronicles II 25:5 In-Context

3 And it came to pass, when the kingdom was established in his hand, that he slew his servants who had slain the king his father.
4 But he slew not their sons, according to the covenant of the law of the Lord, as it is written, as the Lord commanded, saying, The fathers shall not die for the children, and the sons shall not die for the fathers, but they shall die each for his own sin.
5 And Amasias assembled the house of Juda, and appointed them according to the houses of their families for captains of thousands and captains of hundreds in all Juda and Jerusalem: and he numbered them from twenty years old and upwards, and found them three hundred thousand able to go out to war, holding spear and shield.
6 Also he hired of Israel a hundred thousand mighty a hundred talents of silver.
7 And there came a man of God to him, saying, O king, let not the host of Israel go with thee; for the Lord is not with Israel, all the sons of Ephraim.

The Brenton translation of the Septuagint is in the public domain.