Wahhabi movement
The Arabic word "najd" generally means a highland. It can also refer, as a proper noun, to the region of Najd in Saudi Arabia. Some medieval Islamic scholars, who lived before the Wahhabi movement originating in the 18th century CE, wrote different interpretations of what this hadith could be referring to. Contemporarily, this hadith is widely understood to refer to the Wahhabi movement. Unsurprisingly, modern Salafi scholars deny this, since it would condemn their own ideology, and instead claim that it is referring to Iraq. It is notable that Iraq is not a highland, but an alluvial plain.