Or HaChaim on Genesis 37:13/אור החיים על בראשית ל״ז:י״ג

1 לכה ואשלחך אליהם, "come let me send you to them;" The word לכה implied that Joseph should go visit his brothers. In the event he had qualms, however, Jacob added that he would make him a שליח של מצוה, a messenger on a divine mission, i..e fulfilling the commandment of obeying his father. This would protect him against harm (compare Pessachim 8).