If thou hast done foolishly - And who has not, at one time or other of his life?
Lay thine hand upon thy mouth - Like the leper; and cry to God, Unclean! unclean! and keep silence to all besides. God will blot out thy offense, and neither the world nor the Church ever know it, for he is merciful; and man is rarely able to pass by a sin committed by his fellows, especially if it be one to which himself is by nature not liable or inclined.
Lay thine hand upon thy mouth - The act expresses the silence of humiliation and repentance after the sin has been committed, and that of self-restraint, which checks the haughty or malignant thought before it has passed even into words.