(1) (A) and (B) read: “among those who.” (2) (N) and (M) read: “as is the case in the authentic report”; (R), (H), (S), and (W) read: “as this is established in the authentic report.” The hadith is narrated from Abū Hurayra—may Allah be pleased with him—in *Sunan al-Tirmidhī*, 3/387 (Book of Asceticism, Chapter on What Has Been Narrated Concerning the Lifespans of This Ummah). Its wording is: “The lifespan of my ummah ranges from sixty to seventy years.” Al-Tirmidhī states: “This is a *hasan gharīb* hadith transmitted through Abū Sālih from Abū Hurayra. It has also been narrated through more than one route from Abū Hurayra.” The hadith also appears in *Sunan Ibn Mājah*, 2/1415 (Book of Asceticism, Chapter on Hope and the Appointed Term), with the wording: “The lifespans of my ummah range from sixty to seventy years, and few of them exceed that.” Al-Albānī graded the hadith authentic in *Sahīh al-Jāmi al-Saghīr*, 1/354. See also his discussion in *Silsilat al-Ahādīth al-Sahīha*, 2/320 (no. 757). (3) (A) and (B) read: “the scholars and the critical scholars.” (4) “He” is an addition in (A) and (B). (5) Ibn Hajar al-Asqalānī wrote a treatise on this subject entitled *al-Zahr al-Nadir fī Naba al-Khidr* (Fresh Blossoms Concerning the Account of al-Khidr), published in *Majmūat al-Rasāil al-Minbariyya*, 2/195–234. At its conclusion (p. 234), he states: “The conclusion toward which one inclines, in light of the strong evidence, is contrary to the common belief that he remains alive.”