Was hoping that you could tell me the mekor (the main gemara where we learn it out from, pesukim, rambam?) for "Eidus she-i-atah yechol lehazimah ain zeh eidus" and also "kim le derabeh mineh" and where those are found in masseches makkos
chaim, new york city
The Gemara mentions Edus she'Iy Atah Yachol l'hazimah in Sanhedrin 41a, 78a and Bava Kama 75b. The Gemara does not bring a Pasuk for its source. The Rishonim (see Rashi there) explain that since the Torah says "va'Asisem Lo Ka'asher Zamam La'asos" in the section that discusses Edus, we infer that an intrinsic part of the testimony is that we can punish the witnesses with the punishment of Ka'asher Zamam if they are found to be lying. The first Tosfos in Makos mentions the Halachah of Ein Atah Yachol l'Hazimah.
Kim Lei bi'Deraba Minei is discussed at length in the third Perek of Kesuvos Dafim 29-38. Various Derashos are used as sources for this Halachah, depending on the severity of the Aveirah that came in conjunction with a monetary obligation (see Mishnah Kesuvos 36b and Gemara). In Makos the Gemara speaks about Eino Lokeh u'Meshalem on 4a-b, and about other aspects of Kim Lei on 13b.
D. Zupnik