King Solomon's massive national development required vast resources and manpower. To achieve this, a significant levy was placed on the population. There are different ways to understand the nature of this burden. One perspective views it as an explanation of necessity, showing that Solomon did not extort his subjects or take their wealth without justification. Rather, the levy was driven by a clear national interest to fund a series of magnificent building projects [מלבי״ם, רד״ק, אברבנאל]. Alternatively, this burden was not a financial tax at all, but physical forced labor [רש״י, רד״ק, ביאור שטיינזלץ]. While some suggest this labor was drawn from the Israelites [מלבי״ם, מצודת דוד], the primary approach among commentators is that the manual labor fell exclusively on the foreign nations remaining in the land who had not converted. The Israelites themselves were not subjected to this grueling work. Instead, they served the kingdom as soldiers, ministers, and officials, while tens of thousands of foreign laborers worked as quarriers and burden bearers [רלב״ג, רד״ק, ביאור שטיינזלץ, אברבנאל].
This massive workforce was directed toward several central building initiatives, most notably the House of God and the royal palace, alongside the Millo and the walls of Jerusalem. The Millo can be understood through both engineering and functional lenses. From an engineering standpoint, it was an area in the City of David enclosed by retaining walls and filled with earth to level the ground, uniting the city into a single fortified stronghold [רש״י, ביאור שטיינזלץ]. Historically and functionally, it was a wide, beautiful plaza near Zion that King David had intentionally left vacant as a public gathering space for celebrations. It earned the name Millo because it would fill with people. While David built only the areas inward from this plaza, Solomon completed the project [מצודת דוד, רלב״ג, אברבנאל]. Solomon also expanded the wall of Jerusalem along a new route, possibly constructing a system of three concentric inner walls [ביאור שטיינזלץ, אברבנאל]. This expansion served a religious purpose as well, as it sanctified new areas within the city where sacred offerings could be eaten [רלב״ג].
Beyond the capital, the peacetime development boom extended to the cities of Hazor, Megiddo, and Gezer. These locations were developed into vital economic and commercial centers, housing the king's treasures and maintaining his horses and chariots [ביאור שטיינזלץ, אברבנאל]. The rebuilding of Gezer, in particular, was driven by a unique historical event. Pharaoh, the king of Egypt, had previously conquered and burned the city, later presenting the ruins as a dowry for his daughter upon her marriage to Solomon. Because of the sheer devastation inflicted upon Gezer, Solomon was forced to reconstruct the city entirely from its foundations [רלב״ג, אברבנאל].