"When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show others they are fasting. Truly I tell you, they have received their reward in full."
Matthew 6:16
"Is not this the kind of fasting I have chosen: to loose the chains of injustice and untie the cords of the yoke, to set the oppressed free and break every yoke?"
Isaiah 58:6
"Even now," declares the LORD, "return to me with all your heart, with fasting and weeping and mourning."
Joel 2:12