The Church attaches great importance to the feasts of the Apostles, which are preceded by a Vigil (Collect).
St. Matthias, elected by the will of God (Gospel), received Judas' share in the inheritance of the Church which was figured by the Promised Land divided into twelve tribes (Epistle). Called "to give his life" (Gospel), like Jesus, to crown his apostolic career, he suffered martyrdom and was "clothed by God in resplendent glory" (Communion).
Let us ask God to prepare us to celebrate piously the feast of His apostle, St. Matthias.
But I, as a fruitful olive-tree in the house of the Lord, have hoped in the mercy of my God: and I will wait on Thy name, for it is good in the sight of Thy saints. * Why dost thou glory in malice, thou that art mighty in iniquity?
(Psalm 51:10-11,3 from the Introit of Mass)
Grant, we beseech Thee, almighty God, that the solemn feast of Thine apostle Matthias, which we anticipate, may both increase our devotion and advance our salvation.