Theophylact of Ohrid
Catena Aurea · Markusevangelium 1
Now after that John was put in prison, Jesus came into Galilee, preaching the Gospel of the kingdom of God, And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the Gospel.
Or else, the Lord means that the time of the Law is completed; as if He said, Up to this time the Law was at work; from this time the kingdom of God will work, that is, a conversation according to the Gospel, which is with reason likened to the kingdom of heaven. For when you see a man clothed in flesh living according to the Gospel, do you not say that he has the kingdom of heaven, which is not meat and drink, but righteousness and peace and joy in the Holy Ghost? (Rom. 14:17)