Why with regard to the mother is the fetus called "Yerech Eimo", while with regard to a father, the son is called "Karaiy Deavohah"? Why not consistently use either "yerech" or "Karaiy" in both places?
Daniel Gray, Toronto, Canada
The difference is that "Yerech" is Lashon Kodesh, because the concept of "Ubar Yerech Imo" is Tana'ic. "Yoresh
Kara d'Avuha" ("Bera" does not appear in the Gemara) is an Amora'ic concept, and hence the Aramaic.
It also has to do with the concept that is expressed, the Yerech is the place of conception (see also Rashi Bamidbar 5:20 D"H Es Yirecheich), Yerusha which is mainly from the father is expressed as the leg which is an extension of the body.