מדרש על יחזקאל 46:11

"shall there be unto you": Appoint a market commissioner to this end. R. Elazar b. Chananiah b. Chizkiah b. Gurion says: It is written (Ezekiel 46:11) ("the meal-offering,) an ephah (measure) for a bull and an ephah for a ram." Now is the measure for a bull and a ram and a sheep the same? We are hereby apprised that both the large ephah and the small ephah are called "ephah."