Concise Bible Dictionary:

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) we read of bricks being made and burnt; and in Egypt the bricks were made with an admixture of straw. When the Israelites had to find their own straw or stubble and yet make as many bricks per day, it is probable that but little straw was used. Some ancient bricks have been found which had apparently no straw in them. Many of the bricks were stamped with the name of the reigning monarch.
On the monuments in a tomb the process of brick-making in Egypt is fully delineated: a task-master stands over the men with a stick in his hand, as doubtless was the case in the time of Moses (Ex. 5:7-197Ye shall no more give the people straw to make brick, as heretofore: let them go and gather straw for themselves. 8And the tale of the bricks, which they did make heretofore, ye shall lay upon them; ye shall not diminish ought thereof: for they be idle; therefore they cry, saying, Let us go and sacrifice to our God. 9Let there more work be laid upon the men, that they may labor therein; and let them not regard vain words. 10And the taskmasters of the people went out, and their officers, and they spake to the people, saying, Thus saith Pharaoh, I will not give you straw. 11Go ye, get you straw where ye can find it: yet not ought of your work shall be diminished. 12So the people were scattered abroad throughout all the land of Egypt to gather stubble instead of straw. 13And the taskmasters hasted them, saying, Fulfil your works, your daily tasks, as when there was straw. 14And the officers of the children of Israel, which Pharaoh's taskmasters had set over them, were beaten, and demanded, Wherefore have ye not fulfilled your task in making brick both yesterday and to day, as heretofore? 15Then the officers of the children of Israel came and cried unto Pharaoh, saying, Wherefore dealest thou thus with thy servants? 16There is no straw given unto thy servants, and they say to us, Make brick: and, behold, thy servants are beaten; but the fault is in thine own people. 17But he said, Ye are idle, ye are idle: therefore ye say, Let us go and do sacrifice to the Lord. 18Go therefore now, and work; for there shall no straw be given you, yet shall ye deliver the tale of bricks. 19And the officers of the children of Israel did see that they were in evil case, after it was said, Ye shall not minish ought from your bricks of your daily task. (Exodus 5:7‑19)). Bricks brought from Egypt vary in size, from 20 in. to 14 1/4 in. long, 8 3/4 in. to 6 ½ in. wide, and 7 in. to 4 ½ in. thick. There is a brick from Babylon in the British Museum, which bears the inscription in cuneiform characters “I am Nebuchadnezzar, the king of Babylon, the restorer of the temples Sag-ili and Zida, the eldest son of Nabopolassar, king of Babylon.” It measures 13 in. by 13 in., and 4 in. thick. Other bricks from Chaldea are more ancient still.

“109. Egyptian Bricks” From Manners and Customs of the Bible:

Exodus 5:77Ye shall no more give the people straw to make brick, as heretofore: let them go and gather straw for themselves. (Exodus 5:7). Ye shall no more give the people straw to make brick, as heretofore: let them go and gather straw for themselves.
The ancient Egyptian bricks were made of clay moistened with water and then put into molds. After they were sufficiently dry to be removed from the molds, they were laid in rows on a flat spot exposed to the sun, which gradually hardened them. Some were made with straw and some without. Many had chopped barley and wheat straw; others bean haulm and stubble. The use of this crude brick was general in Egypt for dwellings, tombs, and ordinary buildings, walls of towers, fortresses, and sacred inclosures of temples. Even temples of a small size were sometimes built of unburnt brick, and several pyramids of this material are still to be seen in Egypt. The use of stone was confined mainly to temples, quays, and reservoirs.
Egyptian bricks were frequently stamped with the name of the king during whose reign they were made. They differ in size from the Babylonian bricks. They are from fourteen and a half to twenty inches long, from six and a half to eight and three quarter inches wide, and from four and a half to seven inches thick. Several bricks bearing the name of Thothmes III., and plainly showing the chopped straw used in their manufacture, are in the Abbott Collection, which also contains some of the ancient implements which were used in brick-making.

“616. Tempering Clay” From Manners and Customs of the Bible:

This is an allusion to the ancient method of tempering the clay for making bricks. It was done by the feet of the laborer, and was very severe and fatiguing labor. Tit, “clay,” may also be rendered “mire”; and chomer, “mortar,” is not to be understood here in the sense of a cement for bricks, but rather of clay. Henderson accordingly translates the passage, “Enter the mire, and tread the clay.” Keil has, “Tread in the mire, and stamp the clay.” Potter’s clay was tempered in a similar way. “He shall come upon princes as upon mortar, and as the potter treadeth clay” (Isa. 41:2525I have raised up one from the north, and he shall come: from the rising of the sun shall he call upon my name: and he shall come upon princes as upon mortar, and as the potter treadeth clay. (Isaiah 41:25)).