Jamieson, Fausset and Brown on Exodus 1:13-14

13-14. The Egyptians ... made their lives bitter with hard bondage, in mortar, and in brick--Ruins of great brick buildings are found in all parts of Egypt. The use of crude brick, baked in the sun, was universal in upper and lower Egypt, both for public and private buildings; all but the temples themselves were of crude brick. It is worthy of remark that more bricks bearing the name of Thothmes III, who is supposed to have been the king of Egypt at the time of the Exodus, have been discovered than of any other period [Wilkinson]. Parties of these brickmakers are seen depicted on the ancient monuments with "taskmasters," some standing, others in a sitting posture beside the laborers, with their uplifted sticks in their hands.