Not clear though what you mean by "to belabour someone".Gymnasium flagri: gymnasium of the whip = someone (I guess usually a slave) who is often flogged.
Hence: aliquem habere gymnasium: to have someone as a gymnasium = to belabor someone. (Line 410)
Qui asinum non potest, stratum caedit: he who can't beat the donkey, beats the saddle = one always finds a scapegoat.
In Petronius.
inaeroaere alieno esse (Cicero) to be in debt