He had the boil/blister on his arm 'lanced'.
(..) Take him away and put him in irons. We could end this war right now, boy, save thousands of lives. You fight for the Starks, I fight for the Lannisters. Swords or lances, teeth, nails - choose your weapons and let's end this here and now. If we do it your way, Kingslayer... you'd win. (..)2011 TvShow: Game of Thrones Title: Baelor Season: 1 Episode 9