en_tn/2ch/25/05.md

gathered Judah together

Here "Judah" refers to the people who lived in Judah. Alternate translation: "gathered the people of Judah together" (See: rc://en/ta/man/jit/figs-metonymy)

registered them ... numbered them

He had someone write their names on an official list.

by their ancestors' houses

Here the word "houses" is a metonym for the families that lived in them. Alternate translation: "by their ancestors' families" (See: rc://en/ta/man/jit/figs-metonymy)

commanders of thousands and commanders of hundreds

Possible meanings are 1) these numbers represent the exact amount of soldiers that these commanders led. Alternate translation: "commanders of 1,000 soldiers and commanders of 100 soldiers" or 2) the words translated as "thousands" and "hundreds" do not represent exact numbers, but are the names of larger and smaller military divisions. Alternate translation: "commanders of large military divisions and commanders of smaller military divisions" See how you translated a similar phrase in 2 Chronicles 1:2. (See: rc://en/ta/man/jit/translate-numbers)

all of Judah and Benjamin

Here "Judah" and "Benjamin" refer to the people who lived in the wider kingdom of Judah. Alternate translation: "all the people of Judah and Benjamin" (See: rc://en/ta/man/jit/figs-metonymy)

twenty years old and upward

Here numbers that were larger than twenty are spoken of as if they were higher. Alternate translation: "20 years old and older" (See: rc://en/ta/man/jit/figs-metaphor)

found them to be

"learned that there were"

300,000

"three hundred thousand" (See: rc://en/ta/man/jit/translate-numbers)

chosen men

"capable soldiers" or "skilled warriors"