Al-Ḥāfiẓ Ibn Rajab cites a similar report from al-Qurṭubī in al-Fatḥ, as recorded in al-Kawākib (65/1/91). Ibn Taymiyyah likewise states in al-Jawāb al-Bāhir (q9/2): “When the Prophet’s chamber was incorporated into the mosque, its door was sealed and another wall was erected around it so that his ﷺ dwelling would not be turned into a festal site, nor his grave into an idol.”
I must add—with deep regret—that centuries ago a tall green dome was placed over that structure (unless it has since been removed), and the noble grave was encircled with brass lattices, ornate decorations, curtains, and the like—things the very occupant of the grave ﷺ would never have approved.
Indeed, when I visited the Blessed Prophetic Mosque and was honored to convey greetings to him ﷺ in 1368 AH, I saw at the base of the grave’s northern wall a small miḥrāb, with a slightly raised platform behind it, clearly marking out a special spot for prayer directly behind the grave! I was astonished that such a pagan-like practice had endured even during the era of the State of Monotheism.