Lent:

Begins on Ash Wednesday. Ends with midday prayer on Holy Saturday.
The resurrection of Jesus is our great salvation. To prepare to celebrate the Feast of the Resurrection (Easter), the church sets aside a period of preparation. In AD 325. the Council of Nicaea recorded the first reference to the specific number of days for Lent: forty. This forty-day preparation was first prescribed for baptismal candidates and became known as Lent (from the Old English word for “spring”). During this period, the candidates were examined in preparation for Baptism at the Easter (or Paschal) Vigil. Later, these forty days were associated with Jesus’ forty days in the desert prior to His temptation (Matthew 4:1-11) and with the forty years the children of Israel spent in the wilderness (Numbers 14:34) and became a period of preparation for every Christian.
Ash Wednesday:
Ash Wednesday begins the observance of Lent. The placing of ashes on the forehead is a sign of penitence and a reminder of human mortality. The Sundays during this season are not “of Lent” but “in Lent.” Thus the Sundays retain an Easter tone and may be less solemn than the midweek services that congregation typically offer. The Observances of Lent are concrete reminders of the greater solemnity of this season, yet Lutherans emphasize the Gospel of Christ as central even to this penitential season.
“Wash me thoroughly from my iniquity, and cleanse me from my sin”
Psalm 51:2