It is lawful to do good on the Sabbath. Through the healing of a man on the Sabbath Jesus taught the same principle that compassion is greater than strict adherence to laws.
I will put my Spirit upon him – Matthew 12:18
I will put my Spirit upon him. The Triune God is referenced here with the Father speaking about the Son being filled with the Spirit. At Jesus' baptism (Matt. 3:16) the Spirit descended on Jesus and then led him into the wilderness (Matt. 4:1). Though Matthew does not highlight this theme, after Jesus' ascension the Spirit indwells, guides, and empowers Jesus' disciples (John 14:16-17; Acts 13:2; Rom. 8:9-13; 1 Cor. 3:16-17; Eph. 5:18)
My beloved one - Matthew 12:18
My beloved one, in whom my soul is well pleased. This is the same way Jesus is described in Matt. 3:17 and 17:5. At this important turning point in Jesus' ministry (see note on Matt. 13:1-53) Matthew once again (cf. Matt. 4:14-16) shows that Jesus' ministry is the fulfillment of a prophecy from Isaiah (Isa. 42:1-4). This prophecy promised that God would send his chosen Servant to bring God's blessing to all nations (Matt 12:18, 20).
Hope of the Gentiles – Matthew 12:21
In his name all the Gentiles will have a certain hope. Similar to the prophecy from Isa. 9:1-2 quoted in Matt. 4:14-16, this prophecy about Jesus bringing justice and life to the Gentiles (from Isa. 42:1-4) shows that Jesus' mission (Matt. 28:18-20) was to fulfill the promise God made to Abraham that through his offspring all the nations of the world would receive a blessing (Gen. 12:1-3).
Can this be the Son of David? - Matthew 12:23
"Can this be the Son of David?" God promised that the Messianic age when his kingdom comes to the earth would be a time of healing and restoration and that the Messiah would be a descendant of King David (2 Sam. 7:12-16; Ps. 132:11). When people saw Jesus' amazing miracles they hoped that he was indeed the Son of David bringing God's kingdom.
Jesus and the Spirit of God – Matthew 12:24-27
Once again, the Pharisees accused Jesus of being empowered by the prince of demons, Beelzebul, because they could not otherwise explain his power (Matt. 9:34; 10:25). Jesus responded by showing the absurdity of their claim and warning them of the judgment coming upon them for rejecting him. Rather than being demonic, his power came from the Spirit (Matt. 3:16; 12:18), meaning that the kingdom of God is now here.
Blasphemy against the Holy Spirit – Matthew 12:31
Blasphemy against the Spirit will not be forgiven. God is abundant in grace and forgives all who repent (Ps. 86:5; Isa. 55:6-7; 1 John 1:9-10). The only unforgivable sin is the very specific act of finally and completely claiming that Jesus' work is demonic, not from the Holy Spirit. This is the rejection of God and if someone dies holding to this position they have committed the blasphemy against the Spirit.
Out of the abundance of the heart – Matthew 12:34
Out of the abundance of the heart his mouth speaks. This was a regular emphasis in Jesus' teachings — that the inner person/heart is what matters the most, not external religious piety (Matt. 5:21-48; 6:1-21; 15:7-11). Jesus challenged the Pharisees that since they were speaking evil against him this reveals their wicked hearts, therefore, their words will condemn them (Matt. 12:37).