Bede the Venerable — as excerpted in the Catena Aurea on Mark 6:6-13

“(ubi sup.) Again, by the two tunics He seems to me to mean two sets of clothes; not that in places like Scythia, covered with the ice and snow, a man should be content with only one garment, but by coat, I think a suit of clothing is implied, that being clad with one, we should not keep another through anxiety as to what may happen.”