In various Islamic and non-Islamic traditions, Khidr is described as an angel, prophet, or wali,[3][4] who guards the sea, teaches secret knowledge[5] and aids those in distress.

[7] The figure of al-Khidr has been syncretized over time with various other figures including Dūraoša[8] and Sorūsh in Iran,[9][10][11] Sargis the General[12][13] and Saint George in Asia Minor and the Levant,[14] Elijah[15] and Samael (the divine prosecutor)[citation needed] in Judaism, Elijah among the Druze, John the Baptist in Armenia, and Jhulelal[16] in Sindh and Punjab in South Asia.

Though not mentioned by name in the Quran, he is named by Islamic scholars as the figure described in Quran 18:65–82 as a servant of God who has been given "knowledge" and who is accompanied and questioned by the prophet Musa (Moses) about the many seemingly unfair or inappropriate actions he (Al-Khidr) takes (sinking a ship, killing a young man, repaying inhospitality by repairing a wall).

Some contemporary scholars have disagreed with this assessment;[23] however some others point to a possible reference to the Mesopotamian figure Utnapishtim from the Epic of Gilgamesh through the Arabization of his nickname, "Hasisatra".

[29] Muslim scholars identify him as Khiḍr, although he is not explicitly named in the Quran and there is no reference to him being immortal or being especially associated with esoteric knowledge or fertility.

Al-Khiḍr's appearance at Muhammad's funeral is related as follows: A powerful-looking, fine-featured, handsome man with a white beard came leaping over the backs of the people till he reached where the sacred body lay.

[41] Al-Tabari seems more inclined to believe that al-Khiḍr lived during the time of Afridun before Moses, rather than traveled as Abraham's companion and drank the water of life.

However, in the stories al-Tabari recounts, Moses claims to be the most knowledgeable man on earth, and God corrects him by telling him to seek out al-Khiḍr.

[46] In Sufi tradition, al-Khiḍr holds a distinguished position as a figure who receives illumination directly from God without human mediation.

He is considered to be alive and many respected figures, shaykhs, and prominent leaders in the Sufi community claim to have had personal encounters with him.

The Moroccan Sufi Abdul Aziz ad-Dabbagh describes al-Khiḍr as acting in the guidance of divine revelation (wahy) as do other saints, without requiring prophethood.

[47] Ahmadi exegeses of the Quran tend to identify the "Servant of God" whom Moses met to be the symbolic representation of Muhammad himself.

Ahmadis believe that the Quranic passage of Moses' encounter with the "Servant of God" is closely linked, contextually, to the subject matter of surah Al Kahf in which his story is cited.

[51] The Druze typically view El Khidr, John the Baptist and Saint George as one and the same, successive reincarnation of one soul, in keeping with their beliefs in these concepts.

[55] In both cases the explanations provided by Christians is that Druzes were attracted to warrior saints that resemble their own militarized society.

[55] The reverence for Saint George, who is often identified with Al-Khidr, is deeply integrated into various aspects of Druze culture and religious practices.

[53] The story of Saint George slaying the dragon is interpreted allegorically, representing the triumph of good over evil and the protection of the faithful from harm.

[citation needed] As Babayan says, "Khizr is related to the Zoroastrian water goddess Anahita, and some of her former sanctuaries in Iran were rededicated to him (Pir-i Sabz)".

[59] But a very recent study has shown that the Qur'anic story is full of Jewish symbols, even if we cannot historically identify its likely original form.

[28] In one of the most influential hypotheses on the source of the al-Khiḍr story, the early twentieth-century Dutch historian Arent Jan Wensinck  [de] argued that the tale was derived from a Jewish legend involving the Talmudic Rabbi Joshua ben Levi and the Holy Prophet Elijah.

When Joshua questions the Prophet, the Prophet explains that he killed the cow as a replacement for the soul of the man's wife, who was due to die that day; that he fixed the wall because there was treasure underneath it that the rich man would otherwise have found while fixing it himself; and that his prayer was because a land under a single ruler is preferable to one with multiple ones.

A damaged and non-standard thirteenth-century Greek manuscript of the Leimōn Pneumatikos, a hagiographical work by the pre-Islamic Byzantine monk John Moschus, includes the conclusion of a narrative involving an angel and a monk, in which the angel explains certain strange actions he had presumably taken in earlier, now lost sections of the narrative.

He had killed the son of another generous host, because he knew that the boy would grow to be a sinner if he reached adulthood but would go to heaven if he died before committing his sins.

[68] French historian Roger Paret points out that the Moschus story is much more closely aligned to the Quranic episode than the Jewish legend; for instance, the angel in the Greek story and the "servant of God" in the Quran are both anonymous and vaguely defined, in contrast to the named figures of the Jewish Elijah or Khiḍr in Islamic exegesis.

"[71] Schwarzbaum also speculated of an ultimately Jewish prototype for Khiḍr, possibly a legend involving Moses becoming a disciple of the future Rabbi Akiva, compiler of the Oral Torah.

[72] While agreeing that the Quranic story "combines disparate elements from motifs current in late antiquity", Wheeler rejects Schwarzbaum's connection between Rabbi Akiva and Khiḍr.

[75] Some scholars, including Wensinck, have argued that certain elements of the story of Moses and Khiḍr show influence from The Epic of Gilgamesh.

Khiḍr is similar to Utnapishtim in that they are both considered immortal—although the former's immortality is mentioned only in later Islamic sources, not the Qur'an, and this immortality only means very long life since in Islam everyone except God will die at the end —and in that Moses encounters Khiḍr at the "meeting place of the two waters", while Gilgamesh visits Utnapishtim at the "mouth of the waters".

While the two figures share characteristic parallels in many ways, historical analysis has shown that it is misleading to consider only this symbolic harmony.

[85] In The Unreasoning Mask by famed science fiction writer Philip José Farmer, while Ramstan, captain of the al-Buraq, a rare model spaceship capable of instantaneous travel between two points, attempts to stop an unidentified creature that is annihilating intelligent life on planets throughout the universe, he is haunted by repeating vision of meeting al-Khiḍr.