The Messenger of Allah ﷺ designated Dhat Irq as the place of ihram for the people of Iraq.
حدثنا هشام بن بهرام المدائني حدثنا المعافى بن عمران عن أفلح يعني ابن حميد عن القاسم بن محمد
أن رسول الله ﷺ وقت لأهل العراق ذات عرق
[Its chain of transmission is sahih] Nasai narrated it, in the chapters on the rites of Hajj, section on the miqat of the people of Egypt, no. 2654, from the hadith of Hisham bin Bahram, through this same route, and Abu Naeem graded it sahih in Hilyat Awliya 4/94. See also no. 1742.