Mark 6:7

And he called unto him the twelve
"His twelve disciples", as some copies read; whom he had before called by his grace, and had appointed and ordained them his apostles, but had not yet publicly sent forth; in order to which, he now called them to him, and gave them their commission, qualifications, and instructions:

and began to send them forth by two and two:
he first sent forth one couple, and then another; the reason of his sending them by pairs, was partly for the sake of company, and that they might be useful and assisting to one another; and partly to show their agreement in doctrine; and that they might be proper and sufficient witnesses of it, whereby it might be established; and the rather, being thus sent by pairs into different parts, their message would be the sooner dispatched, than if they had all went together:

and gave them power over unclean spirits;
that is, to cast them out; as it is expressed in Mt. 10:1, (See Gill on Matthew 10:1); and which is here added in the Syriac and Persic versions. Many things are omitted by this evangelist, which are mentioned by Matthew: he does not give us the names of the twelve apostles; the reason of that indeed may be, because they are related by him in ( Mark 3:16-19 ) , and he did not choose to repeat them here: nor does he take any notice of the places where the apostles were to go, and where not; nor of the persons to whom, or not; as not into the way of the Gentiles, nor into any of the cities of the Samaritans, but to the lost sheep of the house of Israel: nor does he say any thing of the subject matter of their ministry or what they had in charge to publish; as that the kingdom of heaven is at hand, or the Gospel dispensation: nor does he observe the several things they were to do in confirmation of their doctrine and mission; as healing the sick, cleansing lepers, raising the dead, and casting out devils: he only relates the directions given them with respect to their journey, in the following verses; the reason of all which seems to be, because he refers not to the same time as Matthew does, to their appointment and ordination; but to the time they were sent out, and proceeded on their journey.