One of the two who heard John speak and followed Jesus was Andrew, Simon Peter’s brother.
40. Andrew, Simon Peter’s brother. The design of the Evangelist, down to the end of the chapter, is to inform us how gradually the disciples were brought to Christ. Here he relates about Peter, and afterwards he will mention Philip and Nathanael. The circumstance of Andrew immediately bringing his brother expresses the nature of faith, which does not conceal or quench the light, but rather spreads it in every direction.
We have here the turning over of two disciples from John to Jesus, and one of them fetching in a third, and these are the first-fruits of Christ's disciples; see how small the church was in its beginnings, and what the dawning of the day of its great things was. I. Andrew and another with him were the two that John Baptist had directed to Christ, Joh 1:37.
Commenting on John 1:37-42
One of the two which heard John speak,.... The above things, concerning Jesus being the Lamb of God: and followed him; that is, Jesus, as the Syriac and Arabic versions read; and the Persic version, Christ: and the Ethiopic version, "the Lord Jesus"; for not John, but Jesus they followed: was Andrew, Simon Peter's brother: see Mat 4:18 the other, as before observed, might be the writer of this Gospel.