PTMQ 81.b:4[2] :ילפון מקלקלתא‏ : they learned a corrupt thing
See the entire entry for mqlqlh n.f. corrupt matter

PTMQ 81.b:4[2] :ומתקנתא לא ילפון‏ : they didn't learn the proper thing
See the entire entry for məṯaqqənā, məṯaqqantā n.f. proper, fit thing