New Defender's Study Bible Notes
1:14 one accord in prayer. This is the first of at least thirty occasions of prayer mentioned in the book of Acts. The ministry committed to Christ’s disciples is to bear witness of Him in all the world, but this must always be accompanied by “prayer and supplication.”
1:14 with his brethren. Not only Mary, who had been at the cross, but even “His brethren,” who had not believed on Him during His teaching ministry (e.g., John 7:5), were now among the disciples. Christ’s resurrection had apparently convinced them, as well as the others, to believe on Him as Savior and Lord.
1:15 an hundred and twenty. The 120 disciples could be regarded as members of the very first local church. They had not yet received the promised baptism by the Holy Spirit and were, as Christ had instructed, tarrying in Jerusalem, waiting to “be endued with power from on high” (Luke 24:49). However, most of them (perhaps all) had already been baptized in water, either by John the Baptist or by one of the eleven (note John 1:35-37; 4:1-2), and thus were ready to baptize the three thousand new converts on the day of Pentecost (Acts 2:41).