Matthew now recalls a second great feeding miracle in this region of the Decapolis, the region of Tyre & Sidon & Magadan (v. 39) ... the home of Mary Magdalene.
Lest we forget, Matthew tells us about a feeding miracle to 5,000 men [plus women and children] only one chapter prior [Matthew 14:13-21]
The record of this second great feeding miracle indicates that the first miracle with the 5,000 was not an exception. Jesus repeated any miracle that he wished at any time.
Jesus shows mercy upon these 4,000 + people by feeding their physical needs while feeding their souls. You see ... the only way for any soul to be truly satisfied is in Christ Jesus alone.
These 4,000 men + women and children were hungry. Jesus knew this. He had compassion, mercy, upon them. He did not care that they were Gentiles apart from the chosen people of Israel. They were not God's people in that sense, but all humanity is God's. All of us are made by him for HIS glory. So, God the Father, HIS Son Jesus Christ, and God's Spirit provide for us. Jesus provides here in the way that only God can.