“When Jesus heard these things, he marvelled at him, and turned him about, and said unto the people that followed him, I say unto you, I have not found so great faith, no, not in Israel.”
When Jesus heard this, he was amazed at him, and turning to the crowd following him, he said, I tell you, I have not found such great faith even in Israel — Jesus amazed at someone is extremely rare — the only other instance in the Synoptics is his amazement at Nazareth's unbelief (Mark 6:6). The Gentile centurion's faith amazes Jesus; the hometown crowd's unbelief amazes him. The commendation of Gentile faith as exceeding anything found in Israel is the continuation of the Elijah-Elisha illustrations in Nazareth.
Church Fathers on Luke 7:9
When He had strengthened His disciples by more perfect teaching, He goes to Capernaum to work miracles there; as it is said, When he had ended all his sayings, he entered into Capernaum.
Here we must understand that He did not enter before He had ended these sayings, but it is not mentioned what space of time intervened between the termination of His discourse, and His entering into Capernaum. For in that interval the leper was cleansed whom Matthew introduced in his proper place.
But having finished His teaching, He rightly instructs them to follow the example of His precepts. For straightway the servant of a Gentile centurion is presented to the Lord to be healed. Now the Evangelist, when he said that the servant was about to die, did not err, because he would have died had he not been healed by Christ.