Musar zu Wajikra 20:26

Pride can also be recognized in his food and drink, and in his wearing of proud garments — the garments of a heathen — and against this we are warned in the Torah of Moses, as it is said: "You shall not follow the practices of the nation …" (Lev. 20:23), and it is also written: "… Neither shall ye walk in their statues …" (Ibid. 18:3), and it is further said: "Take heed to thyself that thou be not ensnared to follow them …" (Deut. 12:30). All of these precepts concern one matter — warning that Israel should be distinguished from the nations in its garments, speech and customs, and thus it says: "… for I have set you apart from the peoples" (Lev. 20:26).