Theophylact of Ohrid

For as one who had been tried by experience, he feared, lest perhaps when far from Jesus he should again become the prey of evil spirits. But the Lord shows him, that though He is not present with him, He can protect by His grace, for it follows, But Jesus sent him away, saying, Return to thine own house, and show how great things God hath done for thee. But he said not, "how great things I have done for thee," giving us an example of humility, that we should attribute all our righteousness to God.

Catena Aurea by Aquinas ↗

Titus of Bostra

But as He was departing, the man who had been afflicted will not part from his Saviour, for it follows, Now the man out of whom the devils were departed besought him that he might be with him.

Catena Aurea by Aquinas ↗

Augustine of Hippo

But that he, now that he is healed, desires to be with Christ, and it is said to him, Return to thy house, and tell what great things God has done for thee, implies that each should understand, that after the remission of his sins he should return to a good conscience as to his home, and obey the Gospel for the salvation of others, in order that there he may rest with Christ, lest by too early wishing to be with Christ he neglect the ministry of preaching necessary for this redemption of his brethren.

Catena Aurea by Aquinas ↗

Ambrose of Milan

It says, "The herdsmen saw this and fled." Neither professors of philosophy nor leaders of the synagogue can offer any cure when people perish. Christ alone takes away the sins of the people, provided they do not refuse to submit to healing. He does not want to cure the unwilling and soon abandon the weak for whom it seems that his presence is a burden, like the peoples of the Gerasenes. …

Commentary on Luke ↗

Bede

And the man from whom the demons had gone out begged him that he might be with him. But Jesus sent him away, saying, "Return to your home, and tell how much God has done for you." These words can be rightly understood from the Apostle's sentiment when he says, "My desire is to depart and be with Christ, for that is far better; but to remain in the flesh is necessary on your account" (Philippians 1). …

On the Gospel of Luke ↗