Merciful God, who sent your messengers the prophets to preach repentance and prepare the way for our salvation: Give us grace to heed their warnings and forsake our sins, that we may greet with joy the coming of Jesus Christ our Redeemer; who lives and reigns with you and the Holy Spirit, one God, now and for ever. Amen.

According to Hatchett, this collect is based on that for the Third Sunday in Advent in the Book of Common Worship of the Church of South India, although it expresses ideas similar to those for the Third Sunday in Advent from the 1662 Book of Common Prayer.

What I like about it is that it begins by invoking “merciful God” and it puts a positive spin the prophets preaching repentance. But all of the action is in God; first, with God’s mercy and God sending prophets. But it continues in the same vein, with a petition for God’s grace that we might hear the message of the prophets, amend our lives, and greet Christ’s coming with joy.