Bukhari

Explanation:
Here, the Imam rahimahullah has established that the Prophet sallallahu alayhi wa sallam did not perform ablution (wudu) after eating the shoulder of a goat, so likewise, there is no ablution after eating sattu (roasted barley flour), as is mentioned in the previous hadith.

Hadith Commentary:
➊
In this hadith, there is neither mention of sattu (roasted barley flour) and the like, nor is there any statement regarding rinsing the mouth (kuli) and so on.
The commentators of Bukhari have presented various explanations for this:
(1)
This hadith is related to the previous chapter, but following the principle of “chapter within chapter,” a new heading has been established before the previously mentioned hadith to indicate that for cleansing the mouth after consuming things prepared with fire, merely rinsing the mouth is sufficient.
(2)
The mention of the hadith of Maymunah radi Allahu anha here is due to a scribe’s error, because in the version of Farabri, this hadith is mentioned under the previous chapter.
Allamah Ayni has considered this to be the preferred view.
He says that generally, a skilled scribe is chosen for copying a book, and most scribes with beautiful handwriting are ignorant, and such errors can occur from the ignorant.
(‘Umdat al-Qari: 2/582)
(3)
Hafiz Ibn Hajar rahimahullah has written that Imam Bukhari rahimahullah, by mentioning the hadith of Maymunah radi Allahu anha regarding the omission of rinsing the mouth, has indicated its non-obligation; that is, the food consumed was oily, so rinsing the mouth should have been done, but to demonstrate permissibility, the Messenger of Allah sallallahu alayhi wa sallam omitted it.
(Fath al-Bari: 1/408)
There is no doubt that rinsing the mouth is prescribed for cleansing the mouth; rinsing is done to remove the dispersal of particles in sattu and the effects of oiliness in meat.
If those particles dissolve with the saliva in the mouth, or similarly, after some time the oiliness of the meat also disappears, then there remains no need to rinse the mouth. However, if one has to perform prayer immediately after consuming these things, then rinsing the mouth becomes necessary, because the purpose is to cleanse the mouth so that there is no difficulty in recitation.
If, at the time of prayer, the mouth becomes clean by itself for any reason, then rinsing is not required.

➋
Imam Bukhari rahimahullah has brought the hadith of Maymunah under:
“Rinsing the mouth after sattu.”
It appears that, according to him, the narration is concise; even though rinsing the mouth is not mentioned in it, it is included in the intended meaning, because in the previous chapter, he deduced from the non-obligation of ablution after consuming meat that ablution is also not obligatory after consuming sattu, and here it is being clarified that when rinsing the mouth is done after consuming sattu, even though it does not contain oiliness, then rinsing the mouth after consuming meat or other oily substances is even more appropriate.