A.T. Robertson 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)

Was standing (ιστηκε). Same form in verse 5 which see. So also ιστηκεισαν in 18. Picture of Peter standing outside by the door.

Unto the high priest (του αρχιερεως). Objective genitive here, but dative in verse 15.Unto her that kept the door (τη θυρωρω). Old word (θυρα, door, ωρα, care), masculine in 10:3, feminine here, door-keeper (male or female).