Judah begins to describe what he expects will happen to Jacob if he returns to Jacob without Benjamin. Here "come" can be translated as "go" or "return."
The father saying he would die if his son died is spoken of as if their two lives were physically bound together. Alternate translation: "since he said he would die if the boy did not come back" (See: [[rc://en/ta/man/translate/figs-metaphor]])