Chapter 4:12-17 Jesus Begins His Ministry

4:12 Now when Jesus had heard that John was cast into prison, He departed into Galilee;

Now, when Jesus had heard that John was cast into prison - John was cast into prison by Herod;

4:13 And leaving Nazareth, He came and dwelt in Capernaum, which is upon the sea coast, in the borders of Zabulon and Nephthalim:

He came and dwelt in Capernaum a city of Galilee.
which is upon the sea-coast by the sea of Tiberias, or Genesareth
in the borders of Zabulon and Nephthalim: it bordered on both these tribes; 

--it signifies "the village of consolation"; 

--and so it was, whilst the consolation of Israel dwelt there. 

4:14 That it might be fulfilled which was spoken by Esaias the prophet, saying,

That it might be fulfilled which was spoken - Christ's dwelling in Capernaum accomplished a prophecy of the prophet Isaiah 9:1 and He went and dwelt there, that it might be fulfilled.

4:15 The land of Zabulon, and the land of Nephthalim, by the way of the sea, beyond Jordan, Galilee of the Gentiles;

Galilee of the Gentiles - Or of the nations. So called, because it was inhabited by Egyptians, Arabians, and Phoenicians, according to the testimony of Strabo and others. 

The Hebrew גוים goyim, and the Greek εθνων, signify nations; and, in the Old and New Testaments, mean those people who were not descendants of any of the twelve tribes. The word Gentiles, from gens, a nation, signifies the same. It is worthy of remark, that it was a regular tradition among the ancient Jews, that the Messiah should begin His ministry in Galilee.

4:16 The people which sat in darkness saw great light; and to them which sat in the region and shadow of death light is sprung up.

The people which sat in darkness - This is quoted from Isaiah 9:2, where, instead of sitting, the prophet used the word walked.
And to them which sat in the region and shadow of death: 

--the same persons who sit in darkness, 

--sit also in the region of death; 

*for such are dead in trespasses and sins: 

--where there is no spiritual light, 

--there is no spiritual life, 

*and such are in danger of the second death;

It is just with God to take the gospel and the means of grace, from those that slight them and thrust them away. 

Christ will not stay long where He is not welcome. 

Those who are without Christ, are in the dark. 

They were sitting in this condition, a contented posture; they chose it rather than light; they were willingly ignorant.

4:17 From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.

Jesus began to preach, and to say, Repent - Every preacher commissioned by God to proclaim salvation to a lost world, begins his work with preaching the doctrine of repentance.