‘Again on the next day John was standing, and two of his disciples, and he looked on Jesus as he walked and says, “Behold, the Lamb of God”. And the two disciples heard him speak and they followed Jesus.'
The section begins with John reiterating to two of his disciples that Jesus is ‘the Lamb of God'. The repetition emphasises the importance of the idea to the writer. It indicates that the idea of Jesus' atonement was seen by him as crucial. When two of the disciples of John the Baptist heard this they immediately left John to follow Jesus in order to find out more about Him. One of these was Andrew (John 1:40) and the other is unnamed. It is extremely likely that the other was the writer, for he never refers to himself by name, and it explains why he knew the time when it occurred. So it is John the Baptiser who unconsciously has established the nucleus for the twelve Apostles, and he gladly sends them to Jesus. They had been his disciples. Soon they would follow Jesus.
The interchange which now takes place between Jesus and the two is full of subtlety and meaning. At the time it was commonplace, but now the writer sees a deeper significance in the questions and answers.