Green’s Dictionary of Slang

blow, the n.

a form of confidence trick in which the victim is convinced that it is possible to raise the denomination on notes, e.g. from $10 to $100.

[US]C. Himes Imabelle 32: It didn’t surprise Goldy that Jackson had been trimmed on The Blow.
[US]C. Himes Rage in Harlem (1969) 32: [as 1957].