Which preposition to use with raff

of Occurrences 12%

Out of doubt, the poet is bribed of some that have a mess of cream to eat, before my lord go to bed yet, to hold him half the night with raff-raff of the rumming of Elinor.

from Occurrences 1%

In the most obscure alley in Marseilles there is a caf frequented by sailors, riff-raff from the waterfront and thieves.

Which preposition to use with  raff