Well, eye for an eye and an 'F' for fight
Taking an ‘Eye for an eye’ is a common idiom about retribution. The principle is; If someone takes out your eyes, you reciprocate by doing the same to them. This holds true with any wrong. This line plays with the homophonic similarities between ‘Eye’ and ‘I’, by continuing to say ‘F’ if for fight, continuing the letter theme.
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