Acts 1:13

went up into an upper room--perhaps the same "large upper room" where with their Lord they had celebrated the last Passover and the first Supper (Luk 22:12). where abode--not lodged, but had for their place of rendezvous. Peter, &c.--(See on Mat 10:2-4).

The inspired historian begins his narrative of the Acts of the Apostles, I. With a reference to, and a brief recapitulation of, his gospel, or history of the life of Christ, inscribing this, as he had done that, to his friend Theophilus (Act 1:1, Act 1:2). II. With a summary of the proofs of Christ's resurrection, his conference with his disciples, and the instructions he gave them during the forty days, of his continuance on earth (Act 1:3-5). III. With a particular narrative of Christ's ascension into heaven, his disciples' discourse with him before he ascended, and the angels' discourse with them after he ascended (Act 1:6-11). IV. With a general idea of the embryo of the Christian church, and its state from Christ's ascension to the pouring out of the Spirit (Act 1:12-14). V. With a particular account of the filling up of the vacancy that was made in the sacred college by the death of Judas, by the electing of Matthias in his room (Act 1:15-26).

1:13-26 While the apostles waited for the promised gift of the Holy Spirit (1:4-5), the whole company of 120 disciples in Jerusalem engaged in earnest prayer (1:13-14) and then appointed an apostle to replace Judas Iscariot (1:15-26). 1:13 All eleven of the remaining apostles were present (cp. Matt 10:2-4; Mark 3:16-19; Luke 6:13-16). Judas Iscariot is omitted from this list on account of his betrayal and death (Acts 1:18-19).