Bukhari

Hadith Commentary: Qastallani said: These are five hadiths that have been narrated in the chapter regarding the splitting of the moon (shaqq al-qamar). Three individuals are their narrators: Abdullah ibn Mas'ud, Abdullah ibn Abbas, and Ali. Abdullah ibn Mas'ud radi Allahu anhu is only a witness to the narration; as for Anas radi Allahu anhu, he was in Madinah at that time and his age would have been five years, and Ibn Abbas radi Allahu anhuma had not even been born by then. However, apart from these, a group of other Companions also transmitted the incident of the splitting of the moon.

The translator says: If the splitting of the moon had not occurred, and it was revealed in the Qur'an that the moon had split, then all would have considered the Qur'an to be incorrect and would have turned away from Islam. This alone is sufficient as proof for the occurrence of this event, and there is no need for such an interpretation that the past tense here means the future, as in:
﴿وَنُفِخَ فِي الصُّورِ﴾ ()
﴿وَجَاءَ رَبُّكَ وَالْمَلَكُ صَفًّا صَفًّا﴾ ()
because an event that is possible to occur in the future can also be mentioned in the past tense when truthful people testify to its occurrence.

Now, to say that celestial bodies are not susceptible to being split and rejoined is merely the opinion of a self-willed person imitating Aristotle, who did not establish any proof for this. If Aristotle had known that the center of the universe is the sun, and that the earth is also a planet and included among the celestial bodies, that the moon is subordinate to the earth, and that there are great craters on it, he would not have uttered such foolishness.

To say that the earth is not susceptible to being split and rejoined—what does this mean? Even the sun is susceptible to being split and rejoined. Many philosophers say that the earth is a piece of the sun that separated and, due to its own gravity, is held at such a distance from the sun. As for the matter that you have not seen the splitting and rejoining of celestial bodies in your lifetime—what are you, and what is your lifespan, compared to the ancient ones? (Wahidi)

The splitting of the moon by the supplication of the Messenger of Allah sallallahu alayhi wa sallam during his pure life is absolutely certain. A miracle is precisely that which renders human intellect incapable. The miracles of the noble Prophets are true; to deny miracles or to engage in unwarranted interpretations regarding them is a sign of a true believing Muslim.

Hadith Commentary:
➊
Regarding the splitting of the moon (shaqq al-qamar), Imam Bukhari rahimahullah has presented five hadiths, which are narrated from three Companions radi Allahu anhum: Abdullah ibn Mas'ud radi Allahu anhu, Ibn Abbas radi Allahu anhu, and Anas radi Allahu anhu. At that time, Anas radi Allahu anhu was in Madinah Tayyibah, and Ibn Abbas radi Allahu anhu had not even been born yet. Only Abdullah ibn Mas'ud radi Allahu anhu was an eyewitness. In any case, apart from him, several other Companions radi Allahu anhum have also reported the incident of the splitting of the moon.

➋
The splitting of the moon is an absolute certainty (haqq al-yaqin); to interpret it away unjustifiably is contrary to reason. If the incident of the splitting of the moon had not occurred and the Qur'an had mentioned it, then everyone would have called the Qur'an false and turned away from Islam. This alone is sufficient evidence for its authenticity. Therefore, there is absolutely no need for the interpretation that this will occur near the Day of Judgment and that the past tense is being used in the sense of the future. If that were the case, there would have been no need for the people of Makkah to call it magic. The splitting of the moon occurred at the demand of the polytheists. At that time, the Messenger of Allah sallallahu alayhi wa sallam said to all those present:
"Look and bear witness."
When everyone had clearly seen this miracle, the two pieces then rejoined.

➌
It should be clear that this incident took place in Makkah Mukarramah at night. At that time, it would have been daytime in many other countries, so there is no question of this event being visible there. In some countries, it would have been midnight or the end of the night, when most people are asleep; even those who are awake do not constantly look at the moon such that they would witness an event lasting only a few moments. Furthermore, the splitting of the moon would not have made any difference to the light spread over the earth that would have drawn anyone’s attention. Therefore, the absence of mention of this event in the general histories of the world cannot be used to deny it. In addition, in the authentic history of the Indian subcontinent, "Tarikh-i-Firishta," this incident is mentioned: that the Maharaja of Malabar in India saw this event with his own eyes and had it recorded in his diary. This very incident became the reason for his accepting Islam.

➍
In some narrations, it is mentioned that even the polytheists of Makkah sought confirmation of this event from people coming from outside. At that time, people arriving from various regions testified to having seen this incident.

➎
In our view, the most authentic and reliable history is the books of hadith. When this incident is present in them, there is absolutely no need to search for it in other historical books. Moreover, the attention and importance given to historiography in that era is well known to all. Also, when the majority of the world and such historians did not witness it, what would they write? In any case, the incident of the splitting of the moon has occurred. It is a miracle of the Messenger of Allah sallallahu alayhi wa sallam and one of the signs of the Day of Judgment.
And Allah knows best.