The Gemara says Makkos: daf daled amud bais, that we can compare the tzad chumros to find a conection. That is impossible because, the fact is, You can't have a tzad hashaveh if there is a tzad Chumrah. That is why before we said " forget the chumros- they make no difference- and now we say they do?! It tries to compare them by the fact that they both have a chumrah!
Yair, New York, USA
The "impossible" is possible. Moreover, the Gemara does not say to "forget the Chumros." The fact is that the Gemara is trying to refute Tzad ha'Shaveh.
Rav Yehuda learns that every Lav she'Ein Bo Ma'aseh is punished with Malkus from the Tzad ha'Shaveh of Edim Zomemim and Motzi Shem Ra. In a Mah ha'Tzad, if we find a common Chumra which is not found in the case from which we want to learn (through the Mah ha'Tzad), we say that this Halachah is found only in the cases in which it is explicitly written, because of their special nature. The Chachamim learn that it is sufficient to say that the reason why Motzi Shem Ra and Edim Zomemim have Malkus while other Lavim she'Ein Bo Ma'aseh do not, even though they are not similar, is because they have one similarity in that they both have a special Chumra which is not found in the other Lavim which we wish to learn from them. Rav Yehudah holds, on the other hand, that as long as they have nothing specific in common, we can learn the other Lavim from them.