Theophylact of Ohrid

Peter, as one who cared for all and who out of brotherly love was zealous for the benefit of his listeners, and as one who had already received the Church into his trust, asked (the Lord): whether He was speaking this parable "to all." The Lord does not answer his question directly, but in a veiled manner shows that although the parable spoken is common and extends to all believers, whoever they may be, it also applies to you — the apostles and generally those deemed worthy of teaching or leadership. Listen.

Commentary on Luke ↗

Ambrose of Milan

Or else, the form of the first command is a general one adapted to all, but the following example seems to be proposed to the stewards, that is, the priests; and therefore it follows, And the Lord said, Who then is that faithful and wise steward, whom his Lord shall make ruler over his household, to give, them their portion of meat in due season?

Catena Aurea by Aquinas ↗

Bede

But Peter said to him: Lord, are you telling this parable for us, or for everyone? The Lord indeed had previously warned through a parable, both that he would come suddenly, and that they should expect him prepared; but of which of these matters Peter asked, or about both, whom he compared with himself and his companions, when he said, Are you telling this to us, or to everyone? It is not easily clear. …

On the Gospel of Luke ↗

Bonaventure

And Peter said to him. After he had invited all to vigilance in general, here he invites prelates in particular. This indeed he does in this order. For first he commends the vigilance of prelates: second, he reproves insolence, there: But if that servant shall say etc.; third, he aggravates negligence, there: But that servant who knew. Commending then the vigilance of prelates, first he commends it with respect to the prerogative of merit; second, with respect to the excellence of the reward; there: Blessed is that servant. …

Commentary on Luke, Chapter 12 ↗