Pronouns typically follow antecedent rules, which would make “He” refer to the “Heart.” If the Heart is questioning whether or not he bore the “great pain,” then this suggests that the Heart is so exhausted that he cannot remember when the pain occurred. This lack of memory, coupled with “Yesterday, or Centuries before,” indicates that the great pain has altered the speaker’s perception of time. Whether the pain was yesterday or many years ago, the effects are still being felt.
The speaker personifies another part of the body in this line by referring to the “Heart” as if it could speak. To speak of a heart as “stiff” seems oxymoronic, because a living heart is in constant, regular, necessary motion. The adjective then connects the heart to the nerves and the “great pain” to demonstrate the shock that has penetrated the living components of the speaker, almost causing them to cease functioning.
In the body, nerves act as sensory receptors and send information to the central nervous system and the brain. This word connects to “pain” from earlier, because nerves are the pathway to one’s experience of pain. Furthermore, the speaker personifies the “Nerves” by having them sit as if in a ceremony, which suggests an image of stillness or quiet.
