The phrase "of an ephah of fine flour mixed with oil" is understood from earlier in the sentence. "One-tenth" means one part out of ten equal parts. This can be written in modern measurements. Alternate translation: "2 liters of fine flour mixed with oil" or "a tenth of an ephah (which is about 2 liters)" (See: [[rc://en/ta/man/translate/translate-fraction]] and [[rc://en/ta/man/translate/translate-bvolume]])