RobH_en_tn/gen/42/19.md

let one of your brothers be confined in this prison

This can be stated in active form. Alternate translation: "leave one of your brothers here in prison" (See: rc://en/ta/man/translate/figs-activepassive)

but you go

Here "you" is plural and refers to all the brothers that will not stay in prison. Alternate translation: "but the rest of you go" (See: rc://en/ta/man/translate/figs-you)

carry grain for the famine of your houses

Here "houses" stands for families. Alternate translation: "carry grain home to help your family during this famine" (See: rc://en/ta/man/translate/figs-metonymy)