Luke"s unique inclusion of the specific fruits of repentance ( Luke 3:10-14) demonstrates his concern for social justice. To the sincere in the crowd John recommended generously sharing their possessions with the needy (cf. Galatians 5:22-23). The tunic (Gr. chiton) was the short undergarment worn under a robe. The Jews often wore two of them at once if they had two. These undergarments were not what we think of as underwear. They were simply an under layer of clothing. [source][source][source]