Ashes are placed on the forehead in the sign of the cross – a symbol of grief, grief that we have sinned and caused a separation of ourselves from God. The lection from Joel 2:1-2, 12-17 reaches back to that tradition.
It is a religious season of fasting and prayer arising from the ancient Jewish tradition of penance and fasting. It begins the season of Lent, a 40 day period before Easter Sunday (excluding Sundays).