en_tn/gen/43/33.md

The brothers sat before him

It is implied that Joseph had arranged where each brother would sit. You can make clear the implied information. Alternate translation: "The brothers sat across from the man, according to how he arranged their places" (See: rc://en/ta/man/jit/figs-explicit)

the firstborn according to his birthright, and the youngest according to his youth

The "firstborn" and the "youngest" are used together to mean all the brothers were sitting in order according to their age. (See: rc://en/ta/man/jit/figs-merism)

The men were astonished together

"The men were very surprised when they realized this"