Bukhari

Hadith Commentary:
It is said that the name of Khidr was Baliya bin Malkan bin Qani‘ bin ‘Aibah bin Shalikh bin Arfakhshad bin Sam bin Nuh.
He was born before Ibrahim.
It is narrated from Ibn ‘Abbas radi Allahu anhu that he was a direct son of Adam, and there are also various other narrations.
According to Qastallani, most scholars and Sufis say that he is alive, but Imam Bukhari rahimahullah and the verifying scholars of the Ahl al-Hadith have said otherwise.
And Allah knows best what is correct.
The greening of the earth where he sat was his miracle (karamah).
The miracles (karamat) of the friends of Allah (awliya Allah) are true, provided they are authentically established.
They should not be fabricated; rather, such miracles are purely a gift from Allah Ta‘ala.
The friends of Allah are always in need of Him.
In the explanation of “furwah bayda’” (white fur), Imam Ibn Hajar rahimahullah writes:
“Al-furwah: it is said that it is the skin of the surface of the earth; he sat upon it, and it became green and lush. In the word al-Khidr, both the opening and the breaking of the letter kha’ are permissible. There is a difference of opinion regarding his prophethood. Al-Tha‘labi said he was in the time of Ibrahim al-Khalil, and most have said that he is alive and present today.” – and so on, as in al-Kirmani.
Al-‘Ayni said: “The correspondence is from the hadith in which al-Khidr is mentioned,” as in al-Fath.
The person mentioned in the narration as Nawfal Bikali was a scholar from among the people of Damascus, and it is also narrated that he was the nephew of Ka‘b al-Ahbar. His view was that the companion of Khidr was Musa bin Misha, who, according to the Torah, was a prophet. However, the correct view is that the companion of Khidr was Musa bin ‘Imran.
The “Majma‘ al-Bahrayn” (the meeting of the two seas) that is mentioned is the place where the Persian Sea and the Roman Sea meet.
The fish that was prepared as food and kept with them—when Musa alayhis salam reached the rock with it, there was a spring of the water of life there, from which the fish became alive and jumped into the river.
The objections of Musa alayhis salam to the actions of Khidr were based on apparent circumstances.
When Khidr expressed the realities, Musa alayhis salam had no choice but to accept.
Further details can be found in the books of tafsir.

Hadith Commentary:
1.
The greening of the land due to the sitting of Khidr was his karamah (miraculous feat). The karamat (miracles) of the awliya (friends of Allah) are true, provided that they are authentically established and not fabricated or self-invented. It should be clear that the karamat of the awliya are purely a gift from Allah, and the awliya are always in need of Allah. Allah Almighty has defined the awliya in these words:
﴿الَّذِينَ آمَنُوا وَكَانُوا يَتَّقُونَ﴾ “Those who believe and fear Allah.” (Yunus: 63/10)
Since there are many levels of faith (iman) and piety (taqwa), accordingly, there are also many levels among the awliya of Allah. In common parlance, awliya Allah are those who are at the highest levels of faith and piety. Among our predecessors, there were some whose temperaments were inclined towards asceticism (zuhd), piety (taqwa), and worship; they were called the ascetics (zuhhad) and the righteous (salihin).

2.
In the third century, when Muslims began to be influenced by Greek and Indian philosophies, this group became inclined towards renunciation of the world and monasticism (rahbaniyyah). After this, the concept of wilayah (sainthood) also changed completely, and this term became specific only for those who engaged in spiritual exercises (riyadah) and seclusion (chilla-kushi), and who were formally attached to the allegiance (bay‘ah) of a particular shaykh. The manifestation of karamat from them was made a necessary condition. Then, when un-Islamic beliefs such as wahdat al-wujud (unity of existence), wahdat al-shuhud (unity of witnessing), and hulul (incarnation) infiltrated our culture, the criterion for wilayah became that the more karamat a person manifested, the higher his rank as a wali would be. Some even claimed that they had a direct connection with Allah and had no need for the Shari‘ah received from the Messenger of Allah (sallallahu alayhi wa sallam). In this way, a batini (esoteric) system was established. The business of pir-muridi (spiritual mentorship and discipleship) began. After this, the path (tariqah) of the religion was considered the essence, and the Shari‘ah was regarded as mere bones and cast aside. From a Shari‘ah perspective, this distinction is baseless and self-invented.