John Chrysostom

Nothing can surpass this praise. This is he that was brought up from Jerusalem with him. This man hath said a greater thing than the prophets; for they call themselves "strangers and foreigners," but this one calleth himself even a prisoner. Just like a prisoner of war he was dragged up and down, and lay at every one's will to suffer evil of them, yea rather worse even than prisoners. …

Homily on Colossians 11 ↗

Theophylact of Ohrid

This is the Aristarchus who was led away together with him from Jerusalem. Paul said more than the prophets, because they called themselves strangers and sojourners, while he calls himself even a prisoner. For indeed, just as a prisoner, he was driven and dragged about, even worse; because captors care for their prisoners as their own property, but him, as an enemy and foe, everyone drove and persecuted. …

Commentary on Colossians ↗

Thomas Aquinas

Then when he says, Aristarchus my fellow prisoner greets you, he shows how those who are remaining with the Apostle greet them. The text is clear. And Mark the cousin of Barnabas, concerning whom you have received instructions. We read in Acts (15:37) that a certain person by the name of John, surnamed Mark, had left Paul and Barnabas when they set out on one of their journeys; however, he later returned to them. Barnabas wanted to take him back, but Paul refused. As a result, Paul and Barnabas went their different ways. …

Commentary on Colossians ↗