Muslim

Hadith Commentary:
Vocabulary of the Hadith:
Kir:
The leather bellows that is attached to the furnace to kindle the fire on top of it, and according to some, the term is also applied to the furnace itself.

Hadith Commentary:
The absolute mujtahid, Hazrat Imam Bukhari rahimahullah, has also established from this hadith that musk is pure and excellent, and he has likened it to a good and righteous friend. Indeed, the company of the righteous makes you righteous, and the company of the wicked makes you wicked. Hazrat Abu Musa Ash'ari radi Allahu anhu accepted Islam in Makkah Mukarramah.
He was a memorizer of the Qur'an and a bearer of the Sunnah of the Messenger (sallallahu alayhi wa sallam).
He used to recite the Divine Speech (kalam Allah) in a special manner and with the melody of Dawud alayhis salam.
All listeners would become absorbed.
Pleased with his recitation, Hazrat Umar radi Allahu anhu appointed him as the governor of Basrah.
He passed away in the year 52 AH, radi Allahu anhu wa ardah.

Hadith Commentary:
In this hadith, the Messenger of Allah (sallallahu alayhi wa sallam) has praised musk and likened it to a good friend. If musk were impure, it would be considered filthy and would not be regarded with esteem.
Imam Bukhari (rahimahullah) has deduced from this hadith the purity of musk; therefore, he has likened a good and righteous companion to the one who carries musk.

Hadith Commentary:
Hafiz Ibn Hajar rahimahullah, under this hadith, states: “And in the hadith is the prohibition of sitting in the company of one whose companionship causes harm in matters of religion and worldly affairs, and the encouragement to sit in the company of one whose companionship brings benefit in both. And in it is the permissibility of selling musk and the ruling of its purity, because the Prophet sallallahu alayhi wa sallam praised it and encouraged it. Thus, in it is a refutation of those who dislike it, etc.” (Fath al-Bari)

That is, from this hadith, the reprehensibility of sitting in such gatherings is established where sitting leads to harm in both religious and worldly matters, and in this hadith, there is also encouragement to sit in beneficial gatherings.

And it is also understood that trading in musk is permissible, and that musk is pure (tahir).

Because the Prophet sallallahu alayhi wa sallam praised it,

And encouraged its acquisition.

It is also understood that Imam Bukhari rahimahullah, by establishing this chapter, has refuted those who do not consider trading in musk permissible and who hold the opinion that it is not pure.

Hadith Commentary:
(1)
This hadith contains a prohibition against keeping the company of a bad companion, because the environment of bad people generally causes others to become bad as well, and it encourages keeping the company of righteous and good people.

(2)
From this, it is also understood that musk (kasturi) is pure and its buying and selling are permissible.
In fact, Imam Hasan al-Basri rahimahullah held it to be disliked.
Imam Bukhari rahimahullah refuted him, stating that his position is not based on reality.
Although it is obtained from the blood of a deer, when the state of the blood changes and it solidifies and begins to emit fragrance, it becomes lawful and pure.

(3)
Musk (kasturi) is pure and its buying and selling are also permissible.
Those who consider its trade impermissible and regard it as impure—their position, in light of the aforementioned hadith, is questionable.
(Fath al-Bari: 4/410)
And Allah knows best.