1
general::
Phrase(s): hand over fist
Fig. [for money and merchandise to be exchanged] very rapidly. • What a busy day. We took in money hand over fist. • They were buying things hand over fist.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Rapidly, at a tremendous rate, as in He's making money hand over fist. This expression is derived from the nautical hand over hand, describing how a sailor climbed a rope. [First half of 1800s]
American Heritage Idioms