William Faulkner incorporates selflessness into the story of the Bundren family from the beginning. The first section of the novel is narrated by Darl. While watching Cash make their mom’s coffin, Darl calls his brother a “good carpenter” multiple times. He claims that their mom couldn’t have asked for a “better box to lie in.”
Cash’s work on their mom’s coffin can be considered selfless. He is doing something to benefit someone else. He’s sacrificing his time for the benefit of another person. The sacrificial aspect of Cash is reinforced with the “carpenter” designation, which possibly alludes to Jesus Christ and his connection to carpentry.
Burning down Gillespie’s barn could also be seen as an act of selflessness. It’s reasonable to argue that by destroying the barn, Darl is trying to spare his family further torment. He is taking it upon himself to relieve the burden of others, particularly Cash, whose leg continues to get worse.
Finally, the overarching journey might be described as an act of selflessness. The Bundren family could have heeded Cora Tull’s advice and not buried Addie in Jefferson. However, to abide by her wishes, the Bundren family endures considerable hardship and losses.
The journey permanently disfigures Cash, leads to the loss of Jewel’s beloved horse, and gets Darl sent to a psychiatric hospital. Besides their dad (who got new teeth and another wife), no one really personally benefited from the journey to Jefferson. Thus, even though the Bundren family routinely comes across as vulgar and hardhearted, their central purpose (fulfilling Addie’s burial wish) remains selfless.