PTBM 10.d:50[2] :אתון עבדין עמי היך אתון עבדין מן חמש רבן ואשכחון עבדין מן עשר רבן‏ : you will work for me so that you do work of five r's and they actually were do work of ten r's
See the entire entry for rbh#3 n.f. a type of large coin (?)