The critical study of classical Persian literature requires rigorous philological scrutiny to distinguish authentic authorial compositions from spurious verses that circulated across manuscript traditions over centuries. An essential step in the study of Saʿdi’s poetry and poetic persona is to distinguish his authentic compositions from those forged at various times and circulated under his name for a range of reasons, including the profound influence he exerted on his readers. One verse attributed to Saʿdi in certain sources gradually became part of the collective memory of the people of Fars and of Iranians more broadly, yet it appears in none of the manuscripts consulted by Dr. Yusofi for his edition of the Saʿdi-nāma (Būstān): “Whether Egypt or Syria, land or sea, all are but villages; Shīrāz alone is a city”. This study first presents the principal sources that transmit the verse either under Saʿdi’s name or anonymously, together with its various recensions and readings. It then offers a detailed account of the textual state of critical editions of Saʿdi’s works, as well as of the numerous manuscripts that contain the verse, in order to estimate when this spurious couplet may have originated. Actually, Textual investigation of the famous couplet attributed to Saʿdi celebrating Shīrāz reveals its absence in early manuscripts of the Būstān. Likely forged by learned scribes during the late ninth or tenth century AH, this apocryphal verse reflects historical perceptions of Shīrāz's metropolitan supremacy documented since the eighth century. The final section considers the forger’s possible motives and examines why Shīrāz is compared specifically with Egypt and Syria, rather than with other cities of the Islamic world. In addition to the many manuscripts of Saʿdi’s works from different periods, the study draws on a number of historical sources to estimate when the conception of Shīrāz as a preeminent metropolis may have taken shape.