For an account of the appointment of the apostles, see the notes at Matthew 10:1-4.
And calleth unto him whom he would - Those whom he chose; whom he was about to appoint to the apostleship. See the notes at John 15:16.
He ordained twelve - The word rendered “ordained” here does not express our notion of ordination to the ministry. It means, literally, “he made” - that is, he “appointed” twelve to be with him.
Twelve - The reason why “twelve” were chosen was, probably, that such a number would be deemed competent witnesses of what they saw; that they could not be easily charged with being excited by sympathy, or being deluded, as a multitude might; and that, being destined to go into all the world, a considerable number seemed indispensable. Perhaps, also, there was some reference to the fact that “twelve” was the number of the twelve tribes of Israel.
Boanerges - This word is made up of two Hebrew words signifying “sons of thunder,” meaning that they, on some accounts, “resembled” thunder. See the notes at Matthew 1:1. It is not known why this name was given to James and John. They are nowhere else called by it. Some suppose it was because they wished to call down fire from heaven and consume a certain village of the Samaritans, Luke 9:54. It is, however, more probable that it was on account of something fervid, and glowing, and powerful in their genius and eloquence.