Many Catholics and Protestants practice Ash Wednesday. There is nothing in scripture that mentions it. Ash is symbolic for repentance. Daniel, Mordecai and others showed from the outside their sorrow, sitting in ash and sackcloth. Even the people of Nineveh sat who were pagans repented in ashes and sackcloth before the Lord. One must have an about face or turn away from their sins. Symbols are outward and if not done from a true heart, we can deceive ourselves.True repentance is from the heart and mind. Jesus reminds us that repenting in secret before the Father will be rewarded openly. Matthew 6:6-8.