Bukhari

Hadith Commentary:

A strange notion has become widespread that after death, a husband holds no more significance for his wife than a stranger or any ordinary man; this is an extremely absurd and incorrect concept. In Islam, the relationship between husband and wife is not so trivial that it would end after death and the man would become a stranger to the woman. Thus, a woman's funeral may be lowered into the grave by her own husband, and, as needed, by other people as well, as is established from this hadith.

Hadith Commentary:
(1)
It is commonly believed among us that after death, the marital bond between husband and wife is severed. However, in Islam, the relationship between husband and wife is not so weak that it would end after death and the man would become a stranger to the woman. Therefore, a husband may lower his wife's body into the grave, just as Ali radi Allahu anhu himself lowered the body of Fatimah radi Allahu anha into the grave. The Messenger of Allah sallallahu alayhi wa sallam also once said to Aisha radi Allahu anha that if you were to die while I am present, I would perform your ritual bath (ghusl), and bury you. (Musnad Ahmad: 144/6)

(2)
If needed, other unrelated (non-mahram) people may also perform the duty of lowering the body into the grave. Imam Nawawi rahimahullah states that the aforementioned hadith is among those from which it is established that only men should perform the duty of burial, even if the deceased is a woman (al-Majmu‘: 253/5, 254, Dar Ihya al-Turath al-Arabi edition), because this has been the practice of Muslims from the time of the Messenger of Allah sallallahu alayhi wa sallam until today. Moreover, men are generally stronger and more resolute for this task. In addition, if women were to do this, some part of their bodies might become exposed before unrelated men, which is not permissible according to Shariah. And Allah knows best.

(3)
The meaning of "lam yuqaarif" (did not commit) as explained by Imam Ibn al-Mubarak from his teacher is a less preferred (marjuh) interpretation, because how could Abu Talhah radi Allahu anhu claim in the presence of the Messenger of Allah sallallahu alayhi wa sallam that he had not committed any sin that night? Even though, in support of this meaning, Imam Bukhari rahimahullah has also cited a Qur’anic verse.