A more prevalent interpretation of Sethe's killing of her child at the end of the novel is one, not of repression, but of expression. Rather than have her child live as a slave, Sethe frees her of this condition by sending her soul into the next world. This act, then, for Sethe is an act of love, an act initiated to defy the world that has oppressed her for so long.
And if she thought anything, it was No. No. Nono. Nonono. Simple. She just flew. Collected every bit of life she had made, all the parts of her that were precious and fine and beautiful, and carried, pushed, dragged them through the veil, out, away, over there where no one could hurt them.
For Sethe, the demarcation between life and death is fragile, no more than a "veil" placed before her children. She acts upon instinct and sends her child to the other side rather than let her be a slave.
Repression and expression is a powerful dynamic in Morrison's Beloved. Slavery becomes the embodiment of repression. The manner in which Schoolteacher and his family abuse and repress slaves is of vital importance. It sets the entire narrative in motion. The expression that the slaves articulated to the repression of slavery was escape.
From this, Sethe expresses a loyalty to Halle, rather than repress the reality of his absence. Sethe takes action, expresses her loyalty to him, and in the process, Sethe suffers more repression as her milk is stolen. One can point to this moment as an instant where the dynamic of repression and expression can be seen in all of its brutality and vitality. The milk is symbolic of the most tender of expressions between mother and child. This is an expression of love. It becomes blighted by repression when it is stolen. Halle sees the entire violation and is incapable of doing anything to stop it. His own repression that denies his expression of love causes him to simply forego expression. The smearing of butter, a more "repressed" form of dairy product, might also embody much in way of the dynamic. The expression of Sethe's milk as a liquid, free to flow and disperse, was expression subject to repression. The butter that Halle uses is contained as a solid, repressed from its dispersive quality. It is here in which the moment of Sethe's violation carries much of the experiences of repression and expression.
Sethe's moment of panic when she sees Schoolteacher is another critical moment that embodies repression and expression. When Sethe perceives her children in danger of having to live the life she lived as a slave, she expresses herself as a response to repression. Interestingly enough, Morrison constructs this moment of expression as further repression as Sethe seeks to kill her children. Being a product of repression, Sethe's act of expression is actually one of repression. She sees her duty as a mother to be a force of repression in order to express her own disdain for a political and social institution of repression.
It might be for this reason that Sethe is described as product of both expression and repression. Morrison describes Sethe as one with "iron eyes and a backbone to match," indicating her condition is one of expression. However, the embodiment of repression that slavery is had "punched the glittering iron out of Sethe's eyes, leaving two open wells." The condition of repression had denied her expression, a theme seen throughout her characterization. Sethe lives a life of repression even as a free woman. Even the way she speaks to herself, seeking to express, is rooted in repression: "Freeing yourself was one thing; claiming ownership of that freed self was another." In what Sethe experienced, her entire being is one where there is a struggle to express as the looming shadow of repression follows her always:"...the one set of plans she made—getting away from Sweet Home—went awry so completely she never dared life by making more." Sethe is a character that avoids expression in her refusal to see today and tomorrow as elements of color. She lives in repression fostered by yesterday and facilitated by black and white. When Paul D reminds her that she is her best thing and seeks to share more "tomorrows," it is a moment in which Sethe finds some notion of expression in "I am?" This ending is one where expression might exist in a world where repression has come to dominate.