Al-ʿUqaylī (1) said: “Most of his reports are fabricated.” Al-Bukhārī (2) said: “His ḥadīths are munkar.” Abū Ḥātim (3) said: “He is extremely weak in ḥadīth; his narrations are rejected.” Ibn ʿAdī (4) said: “Almost everything he transmits concerns the merits of ʿAlī, and he is weak and extreme in his Shiʿite leanings.”

Imām al-Shāfiʿī stated in his Musnad (5): “Al-Qāsim ibn ʿAbd Allāh ibn ʿUmar related to us, from Jaʿfar ibn Muḥammad, from his father, from his grandfather ʿAlī ibn al-Ḥusayn, who said:
‘When the Messenger of Allah ﷺ passed away and people came to offer condolences, they heard a voice saying: “With Allah there is consolation for every calamity, compensation for every loss, and attainment for everything missed. So place your trust in Allah and pin your hopes on Him, for the truly stricken one is he who is deprived of reward.”’
ʿAlī ibn al-Ḥusayn then said, ‘Do you know who that was? That was al-Khiḍr.’”

Al-Shāfiʿī’s teacher, al-Qāsim al-ʿUmari, is abandoned; Aḥmad ibn Ḥanbal (6) and Yaḥyā ibn Maʿīn (7) said, “He lies.” Aḥmad added, “He fabricates ḥadīth.” Moreover, the report is mursal, and a narration of this sort cannot be relied upon here. Allah knows best.

The story has also been transmitted through another weak route from Jaʿfar ibn Muḥammad, from his father, from his grandfather, from his father, from ʿAlī, but it is not sound.

ʿAbd Allāh ibn Wahb reported—from someone who narrated to him—from Muḥammad ibn ʿAjlān, from Muḥammad ibn al-Munkadir—that ʿUmar ibn al-Khaṭṭāb, while performing the funeral prayer over a deceased person, heard a voice calling out, “Do not bury him—may Allah have mercy on you.” He therefore waited until the man joined the row, whereupon the man supplicated for the deceased, saying: “If You punish him, he has sinned much against You; but if You forgive him, he is in desperate need of Your mercy.” When the burial was completed he said: “Glad tidings to you, O occupant of this grave, provided you were not a tax official, collector, treasurer, scribe, or policeman.”

ʿUmar then said, “Seize that man so we may ask him about his prayer and his words—who is he?” The man slipped away from them, and when they looked they found the imprint of his foot measuring a cubit. ʿUmar said, “By Allah, this is al-Khiḍr, about whom the Messenger of Allah ﷺ informed us.” (8) This report contains a suspect narrator, its chain is broken, and a narration of this kind is unsound.

The ḥadīth master Ibn ʿAsākir also related—from al-Thawrī, from ʿAbd Allāh ibn Muḥarrar, from Yazīd ibn al-Aṣamm, from ʿAlī ibn Abī Ṭālib—who said:
“I was performing ṭawāf late one night when I saw a man clinging to the curtains of the Kaʿbah saying: ‘O You who…’”