Green’s Dictionary of Slang

1. (drugs) of drugs, delivered immediately; thus as n. and v.

1955		H. Braddy ‘Narcotic Argot Along the Mexican Border’ in AS XXX:2 87: HAND TO HAND, adj.phr. Delivered immediately.
1969		R.R. Lingeman Drugs from A to Z (1970) 109: hand to hand, to To transfer narcotics at the point of sale, as opposed to ‘drop’, where the buyer picks them up after paying the money.
2001		ONDCP Street Terms 11: Hand-to-hand — Direct delivery and payment.
2005		R. Cea No Lights, No Sirens 103: He did the hand-to-hand dealings in the street, so fast that I actually clocked him slinging Shah’s potent boy to twenty junkies in less than a minute.
2005		G. Pelecanos Drama City 191: The jump-out squad got me on a corner in my own neighborhood, doin’ hand-to-hands.
2010		Codella and Bennett Alphaville (2011) 4: We size up everybody - the steerers calling brands, the dealers making hand-to-hands, and the junkies crawling in feeling bad.

2. in non-drug contexts, direct person-to-person payments.

2004

R. Cooley When Corruption Was King 197: I put together a list of all the judges I had paid off—either ‘hand to hand’ or through a conduit.