Acts 1:13

"And when they were come in," it says, "they went up into an upper room, where they were making their abode:" so they then remained in Jerusalem after the Resurrection: "both Peter, and James, and John:" no longer is only the latter together with his brother mentioned, but together with Peter the two: "and Andrew, and Philip, and Thomas, Bartholomew, and Matthew, and James (the son) of Alphaeus, and Simon Zelotes, and Judas, (the brother) of James." He has done well to mention the disciples: for since one had betrayed Christ, and another had been unbelieving, he thereby shows that, except the first, all of them were preserved.

They durst not appear in the town. They also did well to go up into an upper room, as it became less easy to arrest them at once.

[Daniel 6:10] "Now when Daniel learned of it, that is, of the law which had been enacted, he entered his house, and with the windows in his upper room opened up in the direction of Jerusalem, he continued to bow his knees three times a day and worshipped, and made confession before his God just as he was previously accustomed to do." We must quickly draw from our memory and bring together from all of Holy Scripture all the passages where we have read of domata, which mean in Latin either "walled enclosures" (menia) or "beds" or "sun-terraces," and also the references to anogaia, that is, "upper rooms." For after all, our Lord celebrated the passover in an upper room (Mark 14:15, Luke 22:12), and in the Acts of the Apostles the Holy Spirit came upon the one hundred and twenty souls of believers while they were in an upper room (Acts 1:13). And so Daniel in this case, despising the king's commands and reposing his confidence in God, does not offer his prayers in some obscure spot, but in a lofty place, and opens up his windows towards Jerusalem, from whence he looked for the peace . He prays, moreover, according to God's behest, and also according to what Solomon had said when he admonished the people that they should pray in the direction of the Temple. Furthermore, there are three times in the day when we should bow our knees unto God, and the tradition of the Church understands them to be the third hour, the sixth hour, and the ninth hour. Lastly, it was at the third hour that the Holy Spirit descended upon the Apostles (Acts 2:15) . It was at the sixth hour that Peter, purposing to eat, ascended to the upper room for prayer (Acts 10:9). It was at the ninth hour that Peter and John were on their way to the Temple (Acts 3:1).

Peter, interpreting or knowing: James, supplanter of labor. John, by the grace of God: Andrew, becoming powerful or condemned: Philip, the mouth of widows or the mouth of the lamp: Thomas, the abyss or twin or doubting. Bartholomew, son of him who suspends waters: Matthew, gifted: James son of Alphaeus, supplantation. Simon the Zealot, discipline of life: Judas son of James, he was also called Thaddeus. He names the disciples individually to show that, since they had fallen away at the time of the passion, Judas indeed completely cast himself out from the band of the apostles. But Peter agreed, and through the threefold question was summoned back to the Teacher. And if John is recorded among the same as taking the Mother of Christ, yet with John present to the apostles, she herself was also present.

He does not compile a list of the disciples in vain: but wishing to show that they had suffered something human, yet had not remained in apostasy. For indeed Peter, who had denied, was absolved from his denial by bitter tears, as is made evident from this, that shortly afterwards the spiritual flock was entrusted to him. Thomas, who had been unbelieving, was healed of his unbelief when the wounds and the side were touched with his hands. Therefore, although all the others were present together, Judas alone was missing. And Mary, Mother of God, was present, as indeed was John, who had received her into his house, and the brothers were present. What if Joseph, the bridegroom, had been alive, certainly he would also have been present: especially he, who, when his sons doubted, never doubted concerning the privilege. But it is clear that he had long since died: for he himself was not then present, when his kinsmen wished to see Jesus teaching. For what does he say? "Your mother and your brothers are seeking you outside," (Matt. 12:47) nor is it added: "And your father."

And when they had entered the upper room, they went up where they were staying. It designates a place on high, because they had already ascended from earthly conversation of the Sabbath to the higher realms of knowledge and virtue.

James of Alphaeus, and Simon the Zealot, and Judas of James. Some think that there were two apostles called James, namely James of Zebedee and James of Alphaeus, and that the third James, the brother of the Lord, was not an apostle but the bishop of Jerusalem. That is by no means true, but according to the faith of the Gospels, it should be known that this same James, the son of Alphaeus and an apostle, was in charge of Jerusalem, who was called the brother of the Lord, because he was the son of the Lord’s maternal aunt, of whom John the evangelist mentions. However, he says, “standing by the cross of Jesus were his mother, and his mother’s sister, Mary of Clopas” (John 19). Naming this Mary of Clopas from her father or family. For how could the brother of the Lord be said to be not an apostle but the third James, when Paul also names him an apostle: “But I saw none of the other apostles except James, the brother of the Lord” (Galatians 1)? And the evangelist Mark calls him the same, not the third but the other, saying: “There were also women looking on from afar, among whom were Mary Magdalene, and Mary the mother of James the Younger and Joses, and Salome” (Mark 15). For since "greater" and "lesser" usually provide a distinction not among three but between two, the lesser James is called the son of Alphaeus, in distinction from the greater who was the son of Zebedee. Read the book of blessed Jerome against Helvidius. However, Simon the Zealot is the one who is written in the Gospels as the Canaanite. For Cana interprets as zeal. He was from a village in Galilee, Cana, where the Lord turned water into wine, and after his brother James, he ruled the Church of Jerusalem and at the age of one hundred and twenty ascended the cross under Trajan. He is declared to be according to the flesh a cousin of the Savior, because Hegesippus testified that his father Clopas was the brother of Joseph. And Judas of James, that is, the brother of James, is the same as the one called Thaddeus in the Gospels, and he was sent to Edessa to Abgarus, the king of Osroene, as ecclesiastical history tells. It continues:

And when they had entered the upper room, they went up where they were staying. For in Greek the order of words is also placed thus: And when they had gone into the upper room, they went up where they were staying—Peter and John, and Andrew and James. In Greek the order of names is thus: Peter and Andrew, and James and John, and Simon the Zealot, and Judas the son of James. Histories recount concerning these, in which the passions of the apostles are contained, and many deem them apocryphal, that they preached in Persia, and there were killed by the priests of the temples in the city of Suanir, and they underwent glorious martyrdom. The Book of Martyrology, which is titled with the name and preface of blessed Jerome, although Jerome himself was not the author but the translator, and Eusebius is narrated to have been the author, affirms this as well. Further, Isidore believes that this Simon is the one who ruled the Church of Jerusalem after James the brother of the Lord, and was crowned with martyrdom of the cross under Trajan, being a hundred and twenty years old, whom we also followed formerly in the first book of the Acts of the Apostles, not examining what he wrote scrupulously, but simply listening to his words, believing that he learned these things from certain ancient histories. We dare not deny this even now, especially since he who wrote the aforementioned passions of the apostles has most certainly revealed that he wrote uncertain and false things. For he says that the eunuch of Candace, whom Philip baptized in Judea, was in Ethiopia at the time when Matthew was teaching there and helped him in his teaching, while it is manifest that Candace is the name not of a man, but of a woman, that is, not of the eunuch, but of his mistress, namely the queen of the Ethiopians, who, as we have learned from ancient records, were all commonly called thus in olden times. I wrote in the same work, following Jerome's commentary, and concerning Judas the brother of James, who was also called Thaddaeus, that he was sent to Abgar, king of Osroene, as ecclesiastical history has handed down; but afterward, examining the ecclesiastical history itself more diligently, I found it not written there that Thaddaeus the apostle, one of the twelve, but Thaddaeus one of the seventy disciples, was sent to heal the aforementioned king. I do not think an error should be imputed to me, where, following the authority of great doctors, I believed without doubt what I found in their small works should be accepted.

He prudently enumerates the disciples. Since one of them betrayed, another denied, and a third did not believe, he shows that, apart from the betrayer, all were present.