“Now the names of the twelve apostles are these; The first, Simon, who is called Peter, and Andrew his brother; James the son of Zebedee, and John his brother;”
Matthew 10:2 — Greek Interlinear
Church Fathers on Matthew 10:2
From the healing of Peter’s wife’s mother to this place there has been a continued succession of miracles; and they were done before the Sermon upon the Mount, as we know for certain from Matthew’s call, which is placed among them; for he was one of the twelve chosen to the Apostleship upon the mount. He here returns to the order of events, taking it up again at the healing of the centurion’s servant; saying, 'And calling to him his twelve disciples.'
The Evangelist had related above that the Lord exhorted His disciples to pray the Lord of the harvest to send labourers into His vineyard; and He now seems to be fulfilling what He had exhorted them to. For the number twelve is a perfect number, being made up of the number six, which has perfection because it is formed of its own parts, one, two, three, multiplied into one another; and the number six when doubled amounts to twelve.
For the number twelve, which is made up of three into four, denotes that through the four quarters of the world they were to preach the faith of the holy Trinity.