What is the earliest known reference to one of the 54 Torah portions by name? (Is it ever done in the Talmud, for instance?)
For reference, the 54 Torah portions are:
Bereshit Noach Lech Lecha Vayera Chayye Sarah Toldot Vayetze Vayishlach Vayeshev Miketz Vayigash Vayechi
Shemot Va'era Bo Beshallach Yitro Mishpatim Terumah Tetzaveh Ki Tisa Vayakhel Pekudei
Vayikra Tzav Shemini Tazria Metzora Acharei Mot Kedoshim Emor Behar Bechukkotai
Bamidbar Naso Behaalotecha Shlach Lecha Korach Chukat Balak Pinchas Matot Massei
Devarim Va'etchanan Ekev Re'eh Shoftim Ki Tetze Ki Tavo Nitzavim Vayelech Haazinu V'Zot HaBerachah