Morter

Concise Bible Dictionary:

This is spoken of as early as Genesis 11:33And they said one to another, Go to, let us make brick, and burn them throughly. And they had brick for stone, and slime had they for mortar. (Genesis 11:3), in reference to building the tower of Babel: they used brick for stone and slime for morter. In other places it seems to have been employed more for plastering the walls, morter not being so much needed when the buildings were of stone (Lev. 14:42,4542And they shall take other stones, and put them in the place of those stones; and he shall take other mortar, and shall plaster the house. (Leviticus 14:42)
45And he shall break down the house, the stones of it, and the timber thereof, and all the mortar of the house; and he shall carry them forth out of the city into an unclean place. (Leviticus 14:45)). The rigorous labor of the Israelites in Egypt was in preparing morter as well as making bricks (Ex. 1:1414And they made their lives bitter with hard bondage, in mortar, and in brick, and in all manner of service in the field: all their service, wherein they made them serve, was with rigor. (Exodus 1:14)). Morter was made by treading the clay (Nah. 3:1414Draw thee waters for the siege, fortify thy strong holds: go into clay, and tread the mortar, make strong the brickkiln. (Nahum 3:14)). The work of the false prophets who prophesied peace to Jerusalem when God threatened to bring judgment is compared to building a wall and daubing it with untempered [morter]: God’s wind would blow down the wall (Ezek. 13:10-1510Because, even because they have seduced my people, saying, Peace; and there was no peace; and one built up a wall, and, lo, others daubed it with untempered mortar: 11Say unto them which daub it with untempered mortar, that it shall fall: there shall be an overflowing shower; and ye, O great hailstones, shall fall; and a stormy wind shall rend it. 12Lo, when the wall is fallen, shall it not be said unto you, Where is the daubing wherewith ye have daubed it? 13Therefore thus saith the Lord God; I will even rend it with a stormy wind in my fury; and there shall be an overflowing shower in mine anger, and great hailstones in my fury to consume it. 14So will I break down the wall that ye have daubed with untempered mortar, and bring it down to the ground, so that the foundation thereof shall be discovered, and it shall fall, and ye shall be consumed in the midst thereof: and ye shall know that I am the Lord. 15Thus will I accomplish my wrath upon the wall, and upon them that have daubed it with untempered mortar, and will say unto you, The wall is no more, neither they that daubed it; (Ezekiel 13:10‑15)). This teaches a needed lesson that all that is built for God must be built with God’s materials, otherwise it will not stand (1 Cor. 3:11-1511For other foundation can no man lay than that is laid, which is Jesus Christ. 12Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble; 13Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is. 14If any man's work abide which he hath built thereupon, he shall receive a reward. 15If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire. (1 Corinthians 3:11‑15)).
Brick House in Joppa

From Manners and Customs of the Bible:

There were several kinds of mortar used by the Hebrews. Sometimes they used common mud and clay, mixed with straw chopped and beaten small. This may have been the kind especially referred to in the text. Aphar, “mortar,” is frequently rendered “dust,” and indeed is so translated in the verse preceding, where reference is made to the coating of old mortar which was scraped from the outside of the house. They also had several varieties of calcareous earth, any of which, mixed with ashes, made a good mortar. They likewise prepared an excellent cement of one part sand, two parts ashes, and three parts lime. These ingredients were well pounded, and were sometimes mixed with oil, while at other times the oil was put on as an outer coating.
Mortar was usually mixed by being trodden with the feet, but wheels were sometimes used.

Related Books and Articles:

159. Mortar
Narrator: Chris Genthree