What was St. Matthew the Evangelist's feast day prayer?

This is a prayer that celebrates that occasion but whether St. Matthew himself ever wrote one is difficult to determine.

Prayer to St. Matthew

God of mercy, You chose a tax collector, St. Matthew, to share the dignity of the apostles. By his example and prayers, help us to follow Christ and remain faithful in Your service. We ask this through Our Lord Jesus Christ, Your Son, Who lives and reigns with You and the Holy Spirit, one God, forever and ever. Amen.