In lines 763-841, in the story of Sir Gawain and the Green Knight, we are introduced to many significant symbols. After Sir Gawain's prayer, he notices a castle that is described to be beautiful and situated on green land. Sir Gawain is also introduced to the lord of the castle, who, not coincidentally, greatly resembles the Green Knight we encounter in the beginning of the story.
In this passage, the castle is described as a beautiful, white castle on "grounds fair and green… " Although it is in the middle of winter, ironically the castle is surrounded by green grass. The grounds around the castle have not been affected by the bitter winter, which gives us the impression that this castle is a magical place sheltering supernatural figures. When Sir Gawain rides up to the castle, he asks the porter to get permission from the lord of the castle to allow him in. When the porter does so, he returns and, with many other servants, welcomes Sir Gawain with the utmost respect. The noble squires and the knights of the castle warmly greet him before he is led to the central hall to meet the lord. When the lord of the castle greets Sir Gawain, he tells Sir Gawain that he is welcome to stay in his castle as if it was his own. The passage ends with the two men embracing. It never occurs to Sir Gawain why he is greatly welcomed to this mysterious castle without any interrogation as to what brings him there.
In this passage, when Sir Gawain never puts two and two together with the mysterious castle appearing from nowhere and the uncanny resemblance of the Green Knight and the lord of the castle. Sir Gawain never questions why he is greeted with great respect as if the people of the castle have been expecting him. Soon he will find out his stay is all a test, and his treatment is not just mere courtesy.
Take a look at these difficult words I came across:
The Green Knight meets King Arthur and his Round Table