Or HaChaim on Genesis 45:24/אור החיים על בראשית מ״ה:כ״ד

1 וישלח את אחיו, He sent off his brothers, etc. This means that Joseph sent everybody home, including Benjamin. Benjamin's testimony would convince Jacob most of all; this is why Joseph had already stressed previously (45,12) that Benjamin was a witness that he was Joseph. Now that Yehudah had fulfilled the conditions of his guarantee it is clear that if his bones rattled in his coffin during the years Israel travelled in the desert this was only because he failed to have his vow annulled, as pointed out in Megillah 11.