Genesis 18:6 New English Translation

⁶So Abraham hurried into the tent and said to Sarah, “Quick! Take^[a] three measures^[b] of fine flour, knead it, and make bread.”^[c]

Genesis 18:6 tn The word “take” is supplied in the translation for stylistic reasons. In the Hebrew text the sentence lacks a verb other than the imperative “hurry.” The elliptical structure of the language reflects Abraham’s haste to get things ready quickly.
Genesis 18:6 sn Three measures (Heb “three seahs”) was equivalent to about 20 quarts (22 liters) of flour, which would make a lot of bread. The animal prepared for the meal was far more than the three visitors needed. This was a banquet for royalty. Either it had been a lonely time for Abraham and the presence of visitors made him very happy, or he sensed this was a momentous visit.
Genesis 18:6 sn The bread was the simple, round bread made by bedouins that is normally prepared quickly for visitors.

New English Translation (NET)