Theophylact of Ohrid

"Selling, they brought the price of what was sold." This testifies to the great dignity and great piety of those who brought it, because they did not even dare to place it in their hands, but "laid it at the feet of the Apostles" and made them masters and stewards over what was brought, so that it might be spent as if not from their own possessions, but as if from the common fund. And this delivered the givers from vainglory, and presented a twofold joy to the recipients — relief from poverty and freedom from shame.

Commentary on Acts ↗

Oecumenius

Placing honors at the feet of the apostles, but not on their hands, shows the great honor and reverence of those who brought them. The fact that they did not dare to give them to the hands indicates that they made them stewards and dispensers, as if consuming from common funds, and not as personal gifts through their hands. Moreover, what was placed at the feet constituted honor toward them and removed the reproach of the poverty of those supported. And they gave as if from common funds being administered.

Commentary on Acts ↗

Jerome

Then, as you know, believers sold their possessions and brought the prices of them and laid them down at the apostles' feet: a symbolic act designed to show that people must trample on covetousness.

Letter 71.4 ↗