Jamieson, Fausset and Brown on Genesis 45:22

22. changes of raiment--It was and is customary, with great men, to bestow on their friends dresses of distinction, and in places where they are of the same description and quality, the value of these presents consists in their number. The great number given to Benjamin bespoke the warmth of his brother's attachment to him; and Joseph felt, from the amiable temper they now all displayed, he might, with perfect safety, indulge this fond partiality for his mother's son.