This is a ḥasan ṣaḥīḥ ḥadīth. Abū Maḥdhūrah’s name is Samurah ibn Miʿyar.

Some scholars of knowledge have followed this view regarding the adhān.

It has been narrated from Abū Maḥdhūrah that he used to make the iqāmah single (i.e., without repetition).

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= Ibn Mājah (708) and (809), al-Nasāʾī 2/4–7 and 13–14 and 14, Ibn Ḥibbān (1680) and (1681).
See also what precedes it.

(1) Al-Dāraquṭnī 1/237 reported via the chain of Ibrāhīm ibn ʿAbd al-ʿAzīz ibn ʿAbd al-Malik ibn Abī Maḥdhūrah, from his father, from his grandfather: that the Prophet ﷺ called Abū Maḥdhūrah and taught him the adhān, and commanded him to give the adhān in the prayer niches of Mecca: Allāhu akbar, Allāhu akbar twice, and commanded him to give the iqāmah one by one (i.e., singly).

Al-Dāraquṭnī 1/236 and al-Bayhaqī 1/414 reported via the chain of Ibrāhīm ibn ʿAbd al-ʿAzīz ibn Abī Maḥdhūrah as well, who said: I found my father and my grandfather giving this adhān that I give, and giving this iqāmah, and they would say: The Prophet ﷺ taught it to Abū Maḥdhūrah. He then mentioned the adhān, and said: And the iqāmah is single: Allāhu akbar, Allāhu akbar, ashhadu an lā ilāha illā Allāh, ashhadu anna Muḥammadan rasūl Allāh, ḥayya ʿalā al-ṣalāh, ḥayya ʿalā al-falāḥ, qad qāmat al-ṣalāh, qad qāmat al-ṣalāh, Allāhu akbar, Allāhu akbar, lā ilāha illā Allāh.

Al-Dāraquṭnī 1/238 and al-Ḥāzimī in "al-Iʿtibār" p. (69) reported via the chain of Ibrāhīm ibn ʿAbd al-ʿAzīz ibn ʿAbd al-Malik ibn Abī Maḥdhūrah likewise, from ʿAbd al-Malik ibn Abī Maḥdhūrah, from his father Abū Maḥdhūrah: that the Prophet ﷺ commanded him to make the adhān doubled (i.e., with repetition) and the iqāmah odd (i.e., single).

We say: All of these chains revolve around Ibrāhīm ibn ʿAbd al-ʿAzīz ibn Abī Maḥdhūrah, and he is weak.

Ibn Khuzaymah reported in his "Ṣaḥīḥ," as found in "Ittihāf al-Mahrah" 14/371, via the chain of ʿAbd al-ʿAzīz ibn ʿImrān al-Zuhrī, from Muḥammad ibn ʿAbd al-Malik al-Kinānī, from ʿAbd al-Malik ibn ʿAbd al-ʿAzīz ibn Jurayj, from ʿAbd al-Malik ibn Abī Maḥdhūrah, from his father: that the Prophet ﷺ =