While the Israelites were slaves in Egypt, the Egyptians “kept making their life bitter with hard slavery at clay mortar and bricks.” (Ex 1:14) The mortar was mixed to about the consistency of molasses, usually by trampling it with the feet. Chopped straw was combined with the mortar to increase the cohesiveness of the mixture. Later, in their own land, clay mortar and mud bricks served the Israelites as basic building materials in areas where little good-quality building stone was available.

In Egypt (even up to modern times) mortar used for wall plaster has been composed of two parts clay, one part lime, and one part straw and ashes.