"Afterward came also the other virgins, saying, Lord, Lord, open to us.
Matthew 25: 11-12
"The door is a place of peculiar sanctity and importance. The difference between the outside and the inside is that of two different worlds. In large houses the door-keeper sits at the entrance to answer inquiries and conduct visitors within, and at night he sleeps in a small room within the entrance at the side of the door, keeping guard over the premises. He is charged with the protection of the family. In smaller homes, a servant or family member calls out, "Who is it" If the visitor be a well-known friend, he exclaims, "It is I!" or "Open." The recognized tone of the voice is sufficient and no name is given.
When knocking at a door, an individual did not give their name because it was felt that an impostor or thief might try to gain access by using the name of a family friend. The voice of the one wanting to enter had to be recognized. This was a well-known custom anciently. So in the parable of the foolish virgins, when the Lord says, "I know you not, " he is saying that he does not recognize the virgin's voices. There hadn't been enough geniune interaction that their voices would be familiar.
The door would remain closed. This is quite sobering to think about the importance of having geniune interaction with the Lord that not only He recognize our voice, but we recognize His."
(Donna Nielsen, Beloved Bridegroom)