Mark 7:3 - Coke's Commentary on the Holy Bible

Except they wash their hands oft,— Some render it, up to the wrist. 'Εαν μη πυγμη νιψωνται. Theophylact translates it, up to their elbows; affirming that the word πυγμη denotes the whole of the arm, from the bending to the ends of the fingers: but this sense of the word is altogether unusual: for the word μυγμη properly is, "the hand with the fingers contracted into the palm and made round,—the fist." Theophylact's translation, however, exhibits the Evangelist's meaning; for the Jews, when they washed, held up their hands, and contracting their fingers, received the water that was poured on them by their servants, (see 2 Kings 3:11.) till it ran down their arms, which they washed up to their elbows. To wash with the fist, therefore, is to wash with great care. See Mintert on the word ΠΥΓΜΗ, and Lightfoot's Horae Hebraicae.