and gave them authority over unclean spirits to drive them out
and to cure every disease and every illness.
The names of the Twelve Apostles are these:
first, Simon called Peter, and his brother Andrew;
James, the son of Zebedee, and his brother John;
Philip and Bartholomew,
Thomas and Matthew the tax collector;
James, the son of Alphaeus, and Thaddeus;
Simon the Cananean, and Judas Iscariot
who betrayed Jesus.
Jesus sent out these Twelve after instructing them thus,
“Do not go into pagan territory or enter a Samaritan town.
Go rather to the lost sheep of the house of Israel.
As you go, make this proclamation: ‘The Kingdom of heaven is at hand.’”
For my homily, I gave St. Jerome's two-point interpretation of this passage from the Catena Aurea. Here's the quick summary.
First point - Scripture doesn't contradict itself. So, this sending of the Apostles only to their fellow Jews is not in contradiction with the later sending to "all nations" (Mt 28:19). Rather, it's two steps in the fulfillment of God's one plan for salvation. The Jews already had their special status as God's preistly people, and the Revelation of Scripture, to prepare them for this proclamation of the Kingdom; and indeed, many of them did hear and respond, not least the Apostles themselves. The Gentiles, lacking this relationship with God, would wait for the Resurrection to have the whole Gospel proclaimed to them.
Second point flows from this. Since Scripture doesn't contradict itself, we can't read this passage as any kind of limit on where and when we ourselves proclaim the Kingdom. We're sent everyone by our Baptism and Confirmation, and for the ordained, by our Orders. But, St. Jerome says, the verse should be read spiritually, as an indication of how we proclaim. If we live our lives in the manner of those who don't know Christ ("Gentiles"), or who have accepted only part of the Gospel ("Samaritans"), we can't evangelize effectively. We have to live entirely as disciples of Christ, and evangelize from that standpoint first and foremost, by how we live. Thus we may show in our daily actions, even before we may have a chance to speak, the joy, mercy, grace, and hope of Jesus Christ, to a world starving for His love.