Why does King Arthur ask Sir Pellinore to become his friend after they battle each other?

King Arthur asks Sir Pellinore to become his friend after their battle as a demonstration of chivalric values, emphasizing honor and respect among knights. Recognizing Pellinore's bravery and skill, Arthur seeks to forge alliances rather than create enemies. This act reflects the ideals of camaraderie and loyalty that are central to Arthurian legend, showing that true nobility lies in friendship and mutual respect rather than mere victory in combat.