Cyril of Alexandria

But He does not leave us without instruction: for having found, so to speak, a seasonable opportunity, He frames a profitable and saving discourse; and protesting as it were against them, declares, "Take heed, and keep yourselves from all covetousness." He showed us that pitfall of the devil, covetousness, a thing hateful to God, and which the wise Paul even calls idolatry, perhaps as being suitable for those only who know not God, or as being equal in the balance with the defilement of those men who choose to serve stocks and …

Commentary on the Gospel of Luke, Sermon 89 ↗

Theophylact of Ohrid

Therefore He also added these words: "Take heed, and beware of covetousness," urging us to avoid covetousness as if it were some diabolical pit. And to whom did He say this: "Take heed, and beware of covetousness"? To these two brothers. Since they had a dispute over an inheritance, and probably one of the two had wronged the other, He directs His discourse to them about covetousness. For it is a great evil. Therefore the apostle Paul calls it "idolatry" (Col. …

Commentary on Luke ↗

Bede

And he said to them: "Take heed and beware of all covetousness, for a man's life does not consist in the abundance of his possessions." Just as earlier the Lord had spoken much against blasphemers and hypocrites, so here, on the occasion of this foolish petition, he strives to fortify both the crowds and his disciples against the pestilence of greed, by means of precepts and examples. …

On the Gospel of Luke ↗

Bonaventure

Second, with respect to the dissuasion from avarice, he adds: And he said to them: Take heed and beware of all avarice. Take heed, namely, so as to be provident, and beware, so as to be cautious: Ephesians 5: "See, brethren, how you walk cautiously, not as unwise, but as wise," etc. …

Commentary on Luke, Chapter 12 ↗