Grist Mills

Querns: These hand-operated devices date back to Neolithic times and consist of a flat stone bed and a round stone. The Romans used a heavier version of the quern that was powered by animals or slaves.

Stone mills: These mills were powered by water or wind and used two large stones to grind grain into flour.

Genesis 18:

 
He lifted up his eyes and looked, and behold, three men stood in front of him. When he saw them, he ran from the tent door to meet them, and bowed himself to the earth, and said, "My lord, if I have found favor in your sight, do not pass by your servant.

Let a little water be brought, and wash your feet, and rest yourselves under the tree, while I fetch a morsel of bread, that you may refresh yourselves, and after that you may pass on -- since you have come to your servant." So they said, "Do as you have said." And Abraham hastened into the tent to Sarah, and said, "Make ready quickly three measures of fine meal, knead it, and make cakes." And Abraham ran to the herd, and took a calf, tender and good, and gave it to the servant, who hastened to prepare it. 

Then he took curds, and milk, and the calf which he had prepared, and set it before them; and he stood by them under the tree while they ate.