Or, The priests may with good reason be called the eyes of the Church, since they are considered her watchmen, but the deacons and the rest her hands, for by them spiritual deeds are wrought; the people are the feet of the body, the Church; and all these it behoves not to spare, if they become an offence to the Church. Or, by the offending hand is understood an act of the mind; a motion of the mind is the offending foot, and a vision of the mind is the sinning eye, which we ought to cut off if they give offence, for thus the acts of the limbs are often put in Scripture for the limbs themselves.
Source: Catena Aurea by Aquinas