His word was with power - Εν εξουσιᾳ, With authority. He assumed the tone and manner of a new Lawgiver; and uttered all his doctrines, not in the way of exhortation or advice, but in the form of precepts and commands, the unction of the Holy Spirit accompanying all he said. See on Mark 1:22 (note).

And they were astonished at his doctrine,.... At the matter of it, as well as the manner in which it was delivered, it being so different from the Scribes and Pharisees, they had been used to:

for his word was with power: he spake with great fervency, majesty, and authority, and not with coldness and indifference, and dependence on the sense and authority of others, as their teachers did; and besides, such power went along with the word, that it reached their hearts; and as the Persic version renders it, "he penetrated them with it"; and he also confirmed it by powerful operations, by miraculous works, such as casting out devils, and healing diseases, of which an account follows.

They were astonished (ἐξεπλήσσοντο)

See on Matthew 7:28.

And they were astonished at his doctrine: for his word was with power.

4:31 Came down to Capernaum. Nazareth was on the hills; Capernaum in the deep depression of the Sea of Galilee.

4:31-44 Christ's preaching much affected the people; and a working power went with it to the consciences of men. These miracles showed Christ to be a controller and conqueror of Satan, a healer of diseases. Where Christ gives a new life, in recovery from sickness, it should be a new life, spent more than ever in his service, to his glory. Our business should be to spread abroad Christ's fame in every place, to beseech him in behalf of those diseased in body or mind, and to use our influence in bringing sinners to him, that his hands may be laid upon them for their healing. He cast the devils out of many who were possessed. We were not sent into this world to live to ourselves only, but to glorify God, and to do good in our generation. The people sought him, and came unto him. A desert is no desert, if we are with Christ there. He will continue with us, by his word and Spirit, and extend the same blessings to other nations, till, throughout the earth, the servants and worshippers of Satan are brought to acknowledge him as the Christ, the Son of God, and to find redemption through his blood, even the forgiveness of sins.