What does John 18:1 mean?
The words Jesus has just spoken include the High Priestly Prayer (John 17) as well as His final teachings to the disciples at the Last Supper (John 13—16). During feast days (Deuteronomy 16:16), Jerusalem was overcrowded, so travelers would often camp nearby. Jesus and His followers are spending their nights in a grove on the Mount of Olives (Luke 21:37; John 18:2). Other Gospels identify this location as Gethsemane (Matthew 26:36).Upcoming verses will explain how Judas will lead Jesus' enemies (John 11:57; 12:9–11) to this location. In an era without photography, even well-known figures could be difficult to identify in person. For this reason, those seeking to eliminate Christ needed Judas (Matthew 26:14–16) to indicate where to find Him, as well as point Him out to the arresting guards (John 18:2–3).
John notes that Jesus is in the Kidron brook on the way to the Mount of Olives; he will soon explain Jesus' betrayal by a friend. This echoes a similar moment in the life of David, who was also betrayed by a supposed ally, while crossing Kidron en route to the Mount of Olives (2 Samuel 15:23–31).