The Gemoro discusses the limud of "Bonim Atem", re. Korcha, then says (4th - 5th wide line) "O Eino Ela LeGedida" on which Rashi says "Af LeGedida".
I did not understand this Rashi, which seems to say the maybe the posuk refers to Korcha AND Gedida. I would have learned that the Gemoro refers ONLY to Gedida, as the Gemoro says just below in a different suggestion that maybe the posuk refers to both Korcha and Gedida.
At the outset, there is no reason to say that the start of the Pasuk, "Banim Atem," does not relate to the entire Pasuk. Therefore, the Gemara starts with the assumption, as Rashi points out, that both Karchah and Gedidah are included. It is only because we have a Ribuy of "Am Kadosh" that we are forced to say that it refers to one and not to the other. The Gemara later suggests that it may include both, only by offering the suggestion that Seritah will be excluded; "Banim" will relate to Gedidah and Karchah, and "Am Kadosh" to Seritah.