In describing the Israelites’ slavery in Egypt, the Bible gives but a few clues about the sort of work they were doing. Some of these clues match well with what is known to archaeologists and historians about ancient Egyptian construction. For instance, the Israelites produced bricks and were required to meet specific production quotas; many ancient Egyptian structures were made from mud bricks, and documents mention workers who made these bricks being forced to meet regular quotas. David Falk explores how other evidence can shed light on Israelite slavery:
One verse in the Torah describes the Israelites building actual structures, not only making bricks: “Therefore they set taskmasters over them to oppress them with forced labor. They built supply cities, Pithom and Rameses, for Pharaoh.”
What are supply cities? They cannot simply be coterminous with [the historical] Pithom and Rameses, since these two cities were large with multiple buildings in them, including temples made of stone, [not only brick]. In other words, Pithom and Rameses were cities, but they cannot really be described as “supply” cities, and thus, the verse likely refers to structures inside these cities.
I suggest that the term “supply cities” refers to a series of mud-brick storage depots that were attached to the temples in these two cities (and many others), and which were built to store vast quantities of food that would be used for offerings to the Egyptian gods.
That the Bible refers to these structures as “cities” instead of merely “buildings” is likely a consequence of the magnitude of these projects. The area that these supply depots covered often exceeded by many times the area taken up by the temple itself. . . . [Thus] Pharaoh’s command to force the Israelites to build these temple storage depots was concomitantly a command to make God’s chosen people labor in service to gods other than God.
Read more on theTorah.com: https://thetorah.com/what-kind-of-construction-did-the-israelites-do-in-egypt/