Matthew 15:21-22.
“And Jesus went thence, and departed into the coasts of Tyre and Sidon. And, behold, a woman of Canaan came out of the same coasts, and cried unto Him, saying, Have mercy on me, O Lord, Thou Son of David; my daughter is grievously vexed with a devil.”
But Mark says, that “He could not be hid,” though He had entered into the house. And why did He go at all into these parts? When He had set them free from the observance of meats, then to the Gentiles also He goes on to open a door, proceeding in due course; even as Peter, having been first directed to annul this law, is sent to Cornelius.
But if any one should say, How then, while saying to His disciples, “Go not into the way of the Gentiles,” does He Himself admit her? first, this would be our reply, that what He enjoined upon His disciples, He was not Himself also tied to; secondly, that not in order to preach did He depart; which indeed Mark likewise intimating said, He even hid Himself, yet was not concealed.
For as His not hastening to them first was a part of the regular course of His proceedings, so to drive them away when coming to Him was unworthy of His love to man. For if the flying ought to be pursued, much more ought the pursuing not to be avoided.
See at any rate how worthy this woman is of every benefit. For she dared not even come to Jerusalem, fearing, and accounting herself unworthy. For were it not for this, she would have come there, as is evident both from her present earnestness, and from her coming out of her own coasts.
And some also taking it as an allegory say, that when Christ came out of Judea, then the church ventured to approach Him, coming out herself also from her own coasts. For it is said, “Forget your own people and your father's house.” For both Christ went out of His borders, and the woman out of her borders, and so it became possible for them to fall in with each other: thus He says, “Behold a woman of Canaan coming out of her own coasts.”
The evangelist speaks against the woman, that he may show forth her marvellous act, and celebrate her praise the more. For when you hear of a Canaanitish woman, you should call to mind those wicked nations, who overset from their foundations the very laws of nature. And being reminded of these, consider also the power of Christ's advent. For they who were cast out, that they might not pervert any Jews, these appeared so much better disposed than the Jews, as even to come out of their coasts, and approach Christ; while those were driving Him away, even on His coming unto them.
Source: Homilies on the Gospel of St. Matthew (New Advent)