The Bundrens arrive at their next stop on the way to Jefferson, a farm owned by a man called Gillepsie. Upon arrival, Darl asks Jewel "Whose son are you? Your mother was a horse, but who was your father Jewel?" Jewel becomes angry and repeats again and again that Darl is a "goddamn lying son of a bitch." Darl tells his brother not to call him that and asks again who Jewel's father is.
Here, Darl passive-aggressively reveals his awareness of Jewel's identity as Addie's bastard son, sadistically asking Jewel who is father is. Darl's verbal attack on Jewel, who is highly physical, naturally leaves Jewel infuriated. This reaction only leads Darl to keep provoking his brother, such that we just continue to watch their rivalry grow more tense.
Cash begins to sweat because of his cemented leg and the temperature outside, and politely tells his family members that his leg feels hot. The Bundrens decide to pour water on Cash's leg, after which he repeatedly assures them, "I'm obliged. It feels fine."
Cash's predilection for self-sacrifice is no longer Christ-like but ridiculous to the point of being pathological, as he silently endures the pain of a swollen, broken leg covered in cement. His stoic response is not even a sign of martyrdom but merely calls into question the code of heroic behavior to which Cash subscribes.