The parable of the ten virgins describes five virgins who were wise and prepared for the bridegroom's arrival by bringing oil for their lamps, while five were foolish and unprepared. When the bridegroom came at midnight, the foolish virgins' lamps had gone out because they lacked oil. Though they asked the wise for oil, they were told to go buy it themselves. By the time they returned, the door was shut and they were left outside. The passage emphasizes being prepared and watchful for Christ's return.