The expansion of the ancient Assyrian empire brought about the construction of massive urban centers, adding new royal cities to its growing network. Among these newly established cities was Resen. Its exact historical location remains a mystery, though some identify it with Rish Ain in Aram Naharayim [שד״ל], while others suggest it was Ctesiphon in Persia [תורה תמימה]. A neighboring city, Calah, is similarly identified by some as Karakh [שד״ל]. The very name Resen provides insight into its purpose, as it translates to a horse's bridle. Some commentators explain that the city served as a powerful fortress designed to block the expansion of Nimrod, restraining him just as a bridle holds back an animal [מחוקקי יהודה]. Others view the bridle imagery as a physical connection; just as a bridle links two ends together, Resen was built to bridge and tighten the geographical gap between the cities of Nineveh and Calah [בכור שור].
A significant point of discussion revolves around identifying which of these locations earned the title of the great city. The primary approach among commentators is that this title belongs to Nineveh. This is supported by the Book of Jonah, which explicitly describes Nineveh as a great city to God. Although Calah is mentioned immediately beforehand in the narrative, the sentence structure deliberately breaks the sequence to exclude it; otherwise, the text would have simply described Calah directly as the great city [שפתי חכמים, יריעות שלמה]. Nineveh's supreme importance is already established by being listed first [גור אריה, משכיל לדוד]. Because Resen is the newest city being built in the story, one might easily assume the praise was directed at it, necessitating the clarification that Nineveh is the great city [יריעות שלמה].
Conversely, another perspective argues that the natural flow of the narrative points to Resen as the great city, as it is the central subject of the story [רד״ק, רלב״ג, ברכת אשר]. According to this view, the builder intended for Resen to grow into a massive metropolis that would eventually surpass Nineveh in size, even though Nineveh ultimately remained the central capital [מלבי״ם]. A third approach beautifully merges these ideas, suggesting the creation of a massive ancient metropolis. By building Resen between Nineveh and Calah, an unbroken urban continuum was formed, linking all three into a single, colossal block of buildings. This entire united urban space took on the name of its central hub, collectively becoming known as the great city of Nineveh [העמק דבר, בכור שור, חזקוני, קאסוטו].
On a deeper spiritual and historical level, Asshur earned the privilege of establishing such a vast empire, and later having a prophet sent to Nineveh, because he distanced himself from Nimrod's plans and refused to participate in the sin of the Tower of Babel [חזקוני]. Nevertheless, the frequent conquests and regime changes that later swept through this region, shifting power from Assyria to Babylon and then to Persia, carry a lasting message. They reveal that despite human efforts to build massive, fortified cities, the entire earth belongs to God, and He alone is the one who raises up and brings down kings [רד״ק].