What is "v'Chichesh bah" referring to?
Rashi: It is referring to any one of the five cases 1 mentioned above which he denied and on which he swore falsely.
Pikadon, Tesumes Yad, Gezel, Oshek or Aveidah.
Where is the warning Pasuk - which every punishment requires?
Rashi (in Vayikra 19:11): The Warning appears in the Pasuk there "v'Lo Sechachashu ve'Lo Seshakru Ish ba'Amiso".