Chabad.org — English translation + Rashi
Torah Temimah points to Menachos 75a.
E-Daf.com — Menachos 75a
HebrewBooks / Shas PDF
English: “Fine flour mixed” — this teaches that the flour is mixed, and not [already formed] loaves.
Miyut of mixing stage — belilah is performed on the raw flour, not on formed loaves.
Belilah is of the raw solet, not of shaped challos. The Torah’s language “fine flour mixed” teaches that the oil is worked into the flour itself before any loaves are formed.