Sayyid Ahmad Husamaddin (ra) added such a note about Hazrat Mahdi's (as) birthplace in his Istihracname:
"AN INDIVIDUAL [HAZRAT MAHDI (AS)] WILL COME FROM THE MUSLIMS, AND THE HONOR OF THAT INDIVIDUAL WILL SHED LIGHT LIKE THE RAYS OF THE SUN FROM THE HIGHEST PEAK OF THE CAUCASUS.
(Osman Yüksel Serdengeçti, The City with No Temple, Serdengeçti Publication: VI, p.107)
"A MAN WILL APPEAR IN TRANSOXANIA, HE WILL BE CALLED AL-HARITH (THE LION). One of the commanders of his troops will be known as Mansur. Just as Quraysh prepared the way for the Messenger of Allah (saas), Al-Harith will prepare the way for Al Muhammad (family of Muhammad) or else install them. Every believer has a duty to help him or to obey his call."
(Abu Dawud, Mahdi 1, (2452))
Narrator: Hz. Hilal Ibn Amr (r.a.)
(At-Taj, Ali Nasif al-Husayn, Vol. 5, p. 617)
(Sunan Abu Dawud Translation and Commentary, Şamil Publications: 14/410)