John 18:7-9

‘Again therefore he asked them, “Who are you looking for?” And they said, “Jesus of Nazareth”. Jesus replied, “I have told you that I am he, if therefore you are looking for me let these go their way.” That the word which he spoke might be fulfilled, “of those whom you have given me I lost not one”.'

Jesus' concern for His disciples shines through in these words. He was trying to extricate His disciples from their predicament. His point was that as it was Him Whom they were seeking let them take Him and leave the others alone

‘That the word which He spoke might be fulfilled.' It is clear from this that John views the words of Jesus as on a parallel with the Old Testament Scriptures. The verb is used elsewhere in the Gospel to describe the fulfilment of OT passages (John 12:38; John 13:18; John 15:25; John 17:12; John 19:24 and John 19:36). The phrase parallels John 17:12.

But John does not quote this just as a pedantic fulfilment of Jesus' words taken literally. He is rather saying that it was actually necessary for Jesus to protect His disciples. In their state at that time they may not have been able to cope with beatings and torture and may have turned back. So He delivered them from it. He will not allow us to be tempted above what we are able (1 Corinthians 10:13). Besides it was necessary for them to survive in order to fulfil the task for which they had been chosen.