Bukhari

Hadith Commentary:
At the beginning of Islam, mut‘ah was permissible; regarding this, this verse was revealed.
Later, mut‘ah was made prohibited until the Day of Resurrection.
Mut‘ah refers to that temporary marriage which was contracted for a specified period in exchange for a specified thing.
Now, mut‘ah is absolutely prohibited until the Day of Resurrection, and there is complete consensus of Ahl al-Sunnah on its prohibition.

Hadith Commentary:
➊
In one hadith, the reason for the revelation (shan-e-nuzul) of this verse is described in these words: A man came to the Messenger of Allah (sallallahu alayhi wa sallam) and said, "O Messenger of Allah (sallallahu alayhi wa sallam)! Whenever I eat meat, I am overcome by desire for women, so I have made meat unlawful (haram) for myself." At that time, this verse was revealed.
(Jami‘ at-Tirmidhi, Tafsir al-Qur’an, Hadith: 3054)
From this hadith, it is understood that Abdullah ibn Mas‘ud (radi Allahu anhu), like Abdullah ibn ‘Abbas (radi Allahu anhu), also held the belief that temporary marriage (nikah mut‘ah) was permissible. It is possible that he was not initially aware of its abrogation, but when he learned of its abrogation, he retracted his view, as Hafiz Ibn Hajar (rahimahullah) has mentioned, citing Allamah Isma‘ili, narrations in which his retraction is mentioned.
(Fath al-Bari: 8/150)
➋
It is also possible that Abdullah ibn Mas‘ud (radi Allahu anhu) recited the aforementioned verse for the sake of brevity, meaning that the two testicles are a great blessing from Allah; through them, one experiences the pleasure of lawful intercourse (halal jama‘). In this way, they are included among natural faculties. By becoming castrated, do not make this pleasure unlawful (haram) upon yourself.
And Allah knows best.
➌
In any case, temporary marriage (nikah mut‘ah) was permissible at the beginning of Islam, which was abrogated at the time of the Battle of Khaybar. Then, during the Battle of Awtas, it was permitted for only three days, after which it was permanently prohibited. Its prohibition is established from the Book and the Sunnah.

Chapter of Sahih Bukhari Hadith Number: 5071: «بَابُ تَزْوِيجِ الْمُعْسِرِ الَّذِي مَعَهُ الْقُرْآنُ وَالإِسْلاَمُ:»
Relevance between the Chapter Heading and the Hadith:
Apparently, the connection between the chapter heading and the hadith is difficult, because the chapter mentions the marriage of a poor person, whereas there is no mention of poverty in the hadith. However, if one reflects on the relevance between the chapter heading and the hadith, aspects of their connection become evident. The very first point is that in the narration, «ليس لنا نساء» these words are mentioned, so how can the connection of these words with «تزويج المعسر» be established? Moving forward, Imam Bukhari rahimahullah has mentioned another narration in which these words are found, «ليس لنا شيئي» that we have nothing, meaning we have no wealth, etc., nor do we have wives. From these words, the purpose of the chapter heading appears to be fulfilled, as Hafiz Ibn Hajar rahimahullah has also indicated.

Thus, he writes:
«والذي يظهر ان المراد البخارى المعسر من المال بدليل قول ابن المسعود ”وليس لنا شيء .“» [فتح الباري لابن حجر : 100/9]
Therefore, the intent of Sayyiduna Abdullah ibn Mas'ud radi Allahu anhu was that since we had no means of sustenance and nor did we have wives for this purpose, if the Prophet sallallahu alayhi wa sallam had permitted us to become eunuchs, we would have done so, but he did not grant such permission. Remember! These noble Companions radi Allahu anhum were enriched with the wealth of the Qur'an, Sunnah, and Islam, but they did not have wives, which they were in dire need of. Therefore, it is clear from the explicit indication of the text that the Prophet sallallahu alayhi wa sallam granted them permission to marry in exchange for what they knew of the Qur'an.

Accordingly, Imam Qastallani rahimahullah writes:
«ومطابقة الحديث للترجمه كما قال ابن المنير انه عليه الصلاه والسلام نهاهم عن الاستخصاء ووكلهم الى النكا ح، فلو كان المعسر لا ينكح وهو ممنوع من الاستخصاء لكلف شططاً وكان كل منهم لا بد ان يحفظ شيئا من القران فتعين التزويج بما معهم، فحكم الترجمة من حديث سهل بالتنصيص ومن حديث ابن مسعود بالاستدلال.» [ارشاد الساري لشرح صحيح بخاري : 74/9]
From the clarification of Ibn Munir rahimahullah, it becomes clear that the Prophet sallallahu alayhi wa sallam did not grant these Companions, who were in hardship, permission to become eunuchs at all. Rather, he encouraged those among them who had memorized something of the Qur'an to marry in exchange for that, from which the conformity of the hadith with the chapter heading becomes evident. The first hadith, which is taken from Sahl radi Allahu anhu, was made the explicit text, and the hadith from Ibn Mas'ud radi Allahu anhu was used for inference. Thus, with this subtlety, Imam Bukhari rahimahullah deduced from the chapter heading.
«قلت : والله در هذا الامام مأادق نظره، وأوسع فهمه رحمة الله عليه ورحمته واسعة .»

Hadith Commentary:
The sterilization procedures practiced nowadays also constitute castration, which is absolutely not permissible for a Muslim.
Imam Bukhari rahimahullah has derived the purpose of the chapter from this in such a way that when the Prophet sallallahu alayhi wa sallam forbade castration, then the only lawful means left for fulfilling sexual desire is marriage. Thus, it is understood that even a poor person is permitted to marry.
This has already been explicitly mentioned in the hadith of Sahl radi Allahu anhu.

Hadith Commentary:
(1)
The relevance of this hadith to the chapter heading is that the Messenger of Allah (sallallahu alayhi wa sallam) forbade the noble Companions (radi Allahu anhum) from becoming eunuchs, even though they were in need of wives and were poor and destitute. Each of them had memorized some portion of the Noble Qur’an, so it is as if, in exchange for the Qur’an, they were permitted to marry. The hadith narrated from Hazrat Sahl (radi Allahu anhu) is explicit regarding this matter, and Imam Bukhari (rahimahullah) has deduced evidence from this hadith.

(2)
It is also understood from this hadith that it is forbidden (haram) for a person, whether young or old, to become a eunuch, because it involves cutting off progeny, causing harm, and altering the creation of Allah. The same ruling applies to every animal whose meat is not eaten; however, for those animals whose meat is eaten, it is permissible to castrate them in their childhood so that their meat becomes of better quality.

(3)
It should be clear that modern methods of sterilization are also tantamount to becoming a eunuch, which is in no way permissible for any Muslim.
And Allah knows best.

Hadith Commentary:
(1)
This noble verse indicates the prohibition of celibacy (tabattul) and castration (khisā’), because in both cases, one makes pure and lawful things forbidden upon oneself, which is prohibited in the verse.
(2)
Contracting marriage for a limited period is called mut‘ah.
It was permitted during one military expedition, but ultimately, after the Battle of Awtas, it was definitively and permanently prohibited.
In one narration:
Abdullah ibn Mas‘ud radi Allahu anhu practiced it, then he abandoned it.
Rather, in another narration, it is stated that later, mut‘ah marriage was prohibited.
(Al-Sunan al-Kubra lil-Bayhaqi: 7/207, and Fath al-Bari: 9/150)
(3)
The reason for the revelation (shā’n nuzūl) of this noble verse is narrated from Ibn ‘Abbas radi Allahu anhuma as follows: A man came to the Messenger of Allah sallallahu alayhi wa sallam and said:
“O Messenger of Allah! When I eat meat, I feel desire for women, so I have made meat forbidden upon myself.” At that time, this noble verse was revealed.
(Jami‘ al-Tirmidhi, Tafsir al-Qur’an, Hadith: 3054, and ‘Umdat al-Qari: 14/152)