Objection 1. It would seem that it is not lawful for a bishop to have property of his own. For our Lord said (Matthew 19:21): "If thou wilt be perfect, go sell all [Vulgate: 'what] thou hast, and give to the poor... and come, follow Me"; whence it would seem to follow that voluntary poverty is requisite for perfection. Now bishops are in the state of perfection. Therefore it would seem unlawful for them to possess anything as their own.
Objection 2. Further, bishops take the place of the apostles in the Church, according to a gloss on (Luke 10:1). Now our Lord commanded the apostles to possess nothing of their own, according to Matthew 10:9, "Do not possess gold, nor silver, nor money in your purses"; wherefore Peter said for himself and the other apostles (Matthew 19:27): "Behold we have left all things and have followed Thee." Therefore it would seem that bishops are bound to keep this command, and to possess nothing of their own.
Objection 3. Further, Jerome says (Ep. lii ad Nepotian.): "The Greek kleros denotes the Latin 'sors.' Hence clerics are so called either because they are of the Lord's estate, or because the Lord Himself is the estate, i.e. portion of clerics. Now he that possesses the Lord, can have nothing besides God; and if he have gold and silver, possessions, and chattels of all kinds, with such a portion the Lord does not vouchsafe to be his portion also." Therefore it would seem that not only bishops but even clerics should have nothing of their own.
On the contrary, It is stated (XII, qu. i, can. Episcopi de rebus): "Bishops, if they wish, may bequeath to their heirs their personal or acquired property, and whatever belongs to them personally."
I answer that, No one is bound to works of supererogation, unless he binds himself specially thereto by vow. Hence Augustine says (Ep. cxxvii ad Paulin. et Arment.): "Since you have taken the vow, you have already bound yourself, you can no longer do otherwise. Before you were bound by the vow, you were free to submit." Now it is evident that to live without possessing anything is a work of supererogation, for it is a matter not of precept but of counsel. Wherefore our Lord after saying to the young man: "If thou wilt enter into life, keep the commandments," said afterwards by way of addition: "If thou wilt be perfect go sell" all "that thou hast, and give to the poor" (Matthew 19:17-21). Bishops, however, do not bind themselves at their ordination to live without possessions of their own; nor indeed does the pastoral office, to which they bind themselves, make it necessary for them to live without anything of their own. Therefore bishops are not bound to live without possessions of their own.
Reply to Objection 1. As stated above (184, 3, ad 1) the perfection of the Christian life does not essentially consist in voluntary poverty, but voluntary poverty conduces instrumentally to the perfection of life. Hence it does not follow that where there is greater poverty there is greater perfection; indeed the highest perfection is compatible with great wealth, since Abraham, to whom it was said (Genesis 17:1): "Walk before Me and be perfect," is stated to have been rich (Genesis 13:2).
Reply to Objection 2. This saying of our Lord can be understood in three ways. First, mystically, that we should possess neither gold nor silver means that the preacher should not rely chiefly on temporal wisdom and eloquence; thus Jerome expounds the passage.
Secondly, according to Augustine's explanation (De Consens. Ev. ii, 30), we are to understand that our Lord said this not in command but in permission. For he permitted them to go preaching without gold or silver or other means, since they were to receive the means of livelihood from those to whom they preached; wherefore He added: "For the workman is worthy of his meat." And yet if anyone were to use his own means in preaching the Gospel, this would be a work of supererogation, as Paul says in reference to himself (1 Corinthians 9:12-15).
Thirdly, according to the exposition of Chrysostom [Hom. ii in Rom. xvi, 3, we are to understand that our Lord laid these commands on His disciples in reference to the mission on which they were sent to preach to the Jews, so that they might be encouraged to trust in His power, seeing that He provided for their wants without their having means of their own. But it does not follow from this that they, or their successors, were obliged to preach the Gospel without having means of their own: since we read of Paul (2 Corinthians 11:8) that he "received wages" of other churches for preaching to the Corinthians, wherefore it is clear that he possessed something sent to him by others. And it seems foolish to say that so many holy bishops as Athanasius, Ambrose, and Augustine would have disobeyed these commandments if they believed themselves bound to observe them.
Reply to Objection 3. Every part is less than the whole. Accordingly a man has other portions together with God, if he becomes less intent on things pertaining to God by occupying himself with things of the world. Now neither bishops nor clerics ought thus to possess means of their own, that while busy with their own they neglect those that concern the worship of God.
Source: Summa Theologica (New Advent)