I am not sent. He informs the Apostles that his reason for refusing the woman of Canaan arises out of his desire to devote himself entirely to the Jews to whom alone he was appointed to be a minister of the grace of God. He argues from the call and the command of the Father, that he must not yield any assistance to strangers; not that the power of Christ was always confined within so narrow limits, but because present circumstances rendered it necessary that he should begin with the Jews, and at that time devote himself to them in a peculiar manner. For as I have said in expounding Matthew 10:5, the middle wall of partition (Ephesians 2:14) was not thrown down till after Christ's resurrection that he might proclaim peace to the nations which were aliens from the kingdom of God: and therefore he prohibited the Apostles, at that time, from scattering anywhere but in Judea the first seed of doctrine. Justly therefore, does he affirm that, on this occasion, he was sent to the Jews only, till the Gentiles also followed in the proper order. To the lost sheep of the house of Israel. He bestows the designation of sheep of the house of Israel not on the elect only, but on all who were descended from the holy fathers; for the Lord had included all in the covenant, and was promised indiscriminately to all as a Redeemer, as he also revealed and offered himself to all without exception. It is worthy of observation, that he declares himself to have been sent to LOST sheep, as he assures us in another passage that he came to save that which was lost, (Matthew 18:11.) Now as we enjoy this favor, at the present day, in common with the Jews, we learn what our condition is till he appear as our Savior.

But he answered and said, I am not sent - This answer was made to the woman, not to the disciples.
The "lost sheep of the house of Israel" were the Jews. He came first to them. He came as their expected Messiah. He came to preach the gospel himself to the Jews only. Afterward it was preached to the Gentiles, but the ministry of Jesus was confined almost entirely to the Jews.

I am not sent but unto the lost sheep - By the Divine appointment, I am come to preach the Gospel to the Jews only. There are certain preachers who should learn a lesson of important instruction from this part of our Lord's conduct. As soon as they hear of a lost sheep being found by other ministers, they give all diligence to get that one into their fold: but display little earnestness in seeking in the wilderness for those that are lost. This conduct, perhaps, proceeds from a consciousness of their inability to perform the work of an evangelist; and leads them to sit down in the labors of others, rather than submit to the reproach of presiding over empty chapels. Such persons should either dig or beg immediately, as they are a reproach to the pastoral office; for, not being sent of God, they cannot profit the people.
The wilderness of this world is sufficiently wide and uncultivated. Sinners abound every where; and there is ample room for all truly religious people, who have zeal for God, and love for their perishing follow creatures, to put forth all their strength, employ all their time, and exercise all their talents, in proclaiming the Gospel of God; not only to the lost sheep of the house of Israel, but to a lost World. Nor can such exertions be unsuccessful. There the pure truth of God is preached, many will be converted. Where that truth is preached, though with a mixture of error, some will be converted, for God will bless his own truth. But where nothing but false doctrine is preached, no soul is converted: for God will never sanction error by a miracle of his mercy.

But he answered and said, I am not sent but unto the lost sheep of the (g) house of Israel.
(g) Of the people of Israel, who were divided into tribes, but all those tribes came from one family.

But he answered, and said,.... To his disciples, who knew how limited their commission was, that they were not to go into the way of the Gentiles, not to preach to them, nor perform miracles among them; and therefore could not reasonably expect that either the woman, or they, on her behalf, should succeed in this matter.
I am not sent, but to the lost sheep of the house of Israel; as a priest, or as a Saviour and Redeemer, he was sent to make satisfaction and atonement for the sins of all God's elect, and to obtain eternal redemption and salvation for all of them, whether Jews or Gentiles; but as a prophet, in the discharge of his own personal ministry, he was sent by his Father only to the Jews; he was the "minister of the circumcision", Romans 15:8 that is, a minister to the circumcised Jews; he was sent only to preach the Gospel to them, and work miracles among them, in proof of his Messiahship; and upon their rejection of him, then his apostles were to be sent among the Gentiles; but he himself was sent only to the Jews, here styled "the lost sheep of the house of Israel": by "the house of Israel", is meant the whole body of the Jewish nation, so called from Israel, the name of Jacob their father, from whom they sprung; and by the "lost sheep" of that house, are more especially designed the elect of God among them: for though all the individuals of that house were "lost" persons, considered in Adam, and in themselves, as the rest of mankind, and Christ, in the external ministry of the word, was sent to preach to them all; yet the elect of God are only "sheep": they are the sheep of Christ, of his pasture, and of his hand, whom he has the particular care and charge of; and who, in their natural state, are lost and straying, and could never find their way, or recover themselves from their lost state in Adam, and by their own transgressions; but he came to seek, and to save them, and to these his ministry was powerful and efficacious.

But he answered and said, I am not sent but to the lost sheep of the house of Israel--(Also see on Mark 7:26.)

I am not sent but to the lost sheep of the house of Israel. The Lord's personal mission was to the Jews. Under the first commission his apostles were directed to go only to the Jews (Matthew 10:6). It would be impossible to evangelize the Gentiles without setting aside the Jewish customs, the law of Moses, and arousing the bitterest prejudice of the Jews. Hence it was the divine plan that the Son should "keep the law blameless" during his ministry. It was only when the Jews crucified him "that the handwriting of ordinances was nailed to the cross," the "wall of partition" between Jews and Gentiles broken down, and all prepared for the Great Commission which bade his disciples "go into all the world and preach the gospel to every creature."

I am not sent - Not primarily; not yet.