A pawnbroker’s: alluding to the three blue balls, the sign of that trade: or perhaps to its being two to one that the goods pledged are never redeemed.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Two Thieves Beating a Rogue * Two-handedNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes