I think he seen something like a symbol that has to do with the Scarlet Letter!
Dimmesdale sees a mark in the shape of a letter "A" on Chillingworth's chest, which represents the guilt and sin that Chillingworth carries. This mark symbolizes the burden of guilt that Chillingworth embodies and the destructive nature of seeking revenge.
Chillingworth discovers Dimmesdale's secret sin when he sees a mark in the shape of an "A" on the sleeping Dimmesdale's chest. This confirms his suspicions that Dimmesdale is the father of Hester Prynne's daughter, Pearl.
They saw the letter, A, scarred deeply into his chest, the same place where Hester wears her A.
Chillingworth discovers a mark on Dimmesdale's chest, leading him to believe that Dimmesdale is hiding a secret sin related to the mark. This discovery fuels Chillingworth's suspicion that Dimmesdale is the father of Hester Prynne's child.
Dimmesdale inflicts the scar on his chest as an act of penance for his hidden sin of adultery with Hester Prynne. By publicly revealing his secret guilt through the scarlet letter, he seeks to atone for his sins and find redemption. The scar becomes a visible symbol of his inner torment and desire for honesty and absolution.
How does chillingworths original wish to see justice done change
Dimmesdale escapes Chillingworth by revealing his sin publicly during the Election Day procession, thus freeing himself from Chillingworth's hold over him. By confessing and acknowledging his guilt before the townspeople, Dimmesdale is able to gain his redemption and break free from Chillingworth's psychological torment.
The major physical manifestation of Dimmesdale's guilt is the mark on his chest that is revealed before his death. This is his own personal "scarlet letter" that surfaces due to his guilt.
Dimmesdale climbs the scaffold to relieve the guilt and inner torment he feels for his affair with Hester Prynne. The source of his chest pain is believed to be physical manifestation of his emotional turmoil and guilt, rather than a specific medical condition.
In the marketplace, on the scaffold where Hester Prynne had previously stood with her baby as a punishment for her sin. This is where Dimmesdale finally confesses his own guilt and reveals the scarlet letter A on his chest.
Ailing Rev. Dimmesdale has a habit of clutching his chest over his heart, where he feels intense physical and emotional pain due to the guilt he carries from committing adultery with Hester Prynne.
In "The Scarlet Letter," when Chillingworth enters the minister's room, he sees Arthur Dimmesdale sleeping with his shirt unbuttoned, revealing the Scarlet Letter that Hester Prynne has embroidered on his chest. Chillingworth becomes convinced that Dimmesdale is indeed the father of Hester's child, Pearl, as he had suspected all along.
At the end of Chapter 10 in "The Scarlet Letter," Chillingworth discovers the mark on Dimmesdale's chest, confirming his suspicions of the minister's guilt. This revelation deepens Chillingworth's obsession with tormenting Dimmesdale and seeking revenge.