Expositor's Bible Commentary Commentary John 18:16

"but Peter was standing at the door without. So the other disciple, who was known unto the high priest, went out and spake unto her that kept the door, and brought in Peter." — John 18:16 (ASV)

Peter and an unnamed disciple (possibly John, cf. 13:23–24; 20:2–3) had traced Jesus and his captors back from Gethsemane over the Kidron Valley to the residence of the high priest in Jerusalem. This anonymous disciple was known to the household of the high priest and readily obtained access for himself and Peter; there is evidence that John may have been distantly related to that family. Peter was in the “courtyard,” standing with servants and retainers by a fire (v.18).