Jesus withdrew from Galilee, specifically from the region of Gennesaret (Matthew 14:34), to escape the increasing vexation of the Pharisees and scribes from Jerusalem (Matthew 15:1, Matthew 15:12). This is seen in the verb withdrew, a term used repeatedly in the Gospel narrative. Whenever Jesus avoids a threat because his hour has not yet come, he withdraws himself (Matthew 2:14, Matthew 2:22; Matthew 4:12; Matthew 12:15; Matthew 14:13)
Jesus withdrew from Galilee. The Pharisees and scribes from Jerusalem had pursued Jesus into Galilee with their unbelief and criticism. When they encountered him, their vexation only deepened (Matthew 15:1,Matthew 15:12). This forms the threatening backdrop to the words of Matthew 15:21: And Jesus went away from there and withdrew to the district of Tyre and Sidon.
He withdrew from there
—that is, from the region of Gennesaret (Matthew 14:34) and from Galilee more broadly. In doing so, he also withdrew from the growing climate of opposition. This is evident from the verb withdrew, a term used repeatedly in the Gospel narrative. Whenever Jesus becomes aware of a threat and chooses not to fall victim to it at that moment, he withdraws himself (Matthew 2:14, Matthew 2:22; Matthew 4:12; Matthew 12:15; Matthew 14:13).1
21 Jésus, étant parti de là, se retira dans le territoire de Tyr et de Sidon.