All 3 Uses

affirm
in
The Minister's Black Veil
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...one or two affirmed that there was no mystery at all,
*

affirmed = agreed
A person who watched the interview between the dead and living, scrupled not to affirm, that, at the instant when the clergyman's features were disclosed, the corpse had slightly shuddered, rustling the shroud and muslin cap, though the countenance retained the composure of death.†
His converts always regarded him with a dread peculiar to themselves, affirming, though but figuratively, that, before he brought them to celestial light, they had been with him behind the black veil.†

Definitions:

(1) (affirm as in: I affirm the statement)
to firmly state that something is true
(2) (affirm as in: affirmed her child's efforts)
to demonstrate support or demonstrate the truth of something
(3) (meaning too rare to warrant focus)