Nasai

643. Commentary: It is understood that the time for the adhan is at the break of dawn (tulu‘ al-fajr). For further details, see the introduction of this very book.

Benefits and Issues:
Relevance between the Chapter and the Hadith:
It is evident from the chapter that Imam Bukhari rahimahullah is highlighting the virtue of using the tooth-stick (miswak) on the day of Jumu‘ah (Friday).
The hadith which mentions that if it were not difficult for the ummah, he (sallallahu alayhi wa sallam) would have commanded the use of the tooth-stick for every prayer, the relevance between this hadith and the chapter is that if the use of the tooth-stick had been made obligatory for all prayers, then certainly it would have been even more obligatory for the Friday prayer, because more people gather for the Friday prayer than for the five daily prayers, and it is a large congregation.

The second hadith, narrated from Anas radi Allahu anhu, in which the Prophet sallallahu alayhi wa sallam said: “I have repeatedly emphasized to you the excellence of using the tooth-stick.”
The relevance here is that one should not be negligent or lazy in using the tooth-stick; rather, one should make it a habit. Therefore, the Prophet sallallahu alayhi wa sallam repeatedly clarified its excellence, and also made it clear that it is difficult to use the tooth-stick all the time. Thus, specifying one day for the tooth-stick is not difficult, and among the remaining days, the best day is Friday. On Friday, it is legislated to apply perfume and wear clean clothes, and on this day, the use of the tooth-stick is also included among the best deeds.

◈ Ibn al-Mulaqqin rahimahullah says:
“The reasoning and conformity (with the chapter heading) from this hadith is that when the use of the tooth-stick is established for the five daily prayers, then on the day of Jumu‘ah, in which there is also ritual bath (ghusl) and so on, the use of the tooth-stick is even more established.” [التوضيح، ج8، ص421]

Note:
In light of the aforementioned hadith, Ibn Hazm rahimahullah has inclined towards its obligation, that using the tooth-stick on the day of Jumu‘ah is obligatory, and a statement is also attributed to the hadith scholar Ishaq ibn Rahwayh rahimahullah that:
«هو واجب لكل صلاة فمن تركه عامداً بطلت صلاته»
The use of the tooth-stick is obligatory for every prayer, so whoever deliberately abandons it, his prayer will be invalid. [فتح الباري، ج8، ص123]

◈ However, Ibn Rajab al-Hanbali rahimahullah says:
This attribution of the statement to Ibn Rahwayh is not correct. [فتح الباري، ج8، ص123]
Thus, the relevance between the chapter heading and the hadith is that when using the tooth-stick is legislated for general prayers, then it is even more legislated on the day of Jumu‘ah, because on this day there is special encouragement for cleanliness, ritual bath (ghusl), and the use of perfume.

The third hadith, which is narrated from Sayyiduna Hudhayfah radi Allahu anhu, in which it is established that the Prophet sallallahu alayhi wa sallam used the tooth-stick during the night prayer (tahajjud), the application here is that the night prayer is performed alone, and for the Friday prayer, the use of perfume is commanded, so by greater reason, the command to use the tooth-stick is also included for this prayer. Thus, the conformity of this hadith with the chapter is evident. Further discussion on this hadith will come, in sha Allah, in chapter «طول القيام فى صلاة الليل».

Benefit No. ➊
Imam Ibn Daqiq al-‘Id rahimahullah says:
«الحكمة فى استحباب السواك عند القيام إلى الصلاة كونها حالاً تقرب إلى الله» [فتح الباري ج2 ص478]
“The wisdom behind using the tooth-stick in prayer is that in this state, one attains closeness to Allah, the Exalted.”

◈ Ibn Daqiq al-‘Id further says:
“In using the tooth-stick, there is a great deal of cleanliness and an expression of the honor of worship.”
Ibn Daqiq al-‘Id rahimahullah has derived several important issues from the aforementioned hadith. He has highlighted 32 issues in his juristic commentary on this hadith. See: [شرح الالمام، ج3، ص53 تا 91]

Benefit No. ➋
The blessed teachings of the Prophet sallallahu alayhi wa sallam truly make a person a real human being. The Prophet sallallahu alayhi wa sallam instructed the Muslim to keep his mouth clean at all times. He sallallahu alayhi wa sallam commanded his ummah to use the tooth-stick for every prayer. Brushing with a toothbrush does not clean the teeth as thoroughly; even if it does, a layer of plaque forms on the teeth afterward. The tooth-stick (miswak) is something that is extremely beneficial for all dental diseases.
In Pakistan, in 1985, modern medical research was conducted on various plant twigs used for cleaning teeth. The results regarding the miswak (peelu) were very encouraging. The twigs used for this purpose were compared biologically for their effectiveness against germs. The names of these plants are as follows:
① Neem (Melia Azadirachta Linn)
② Kikar (Acacia Arabica Willd)
③ Phulai (Acacia Modesta Willd)
④ Miswak/Peelu (Salvadora Persica Linn)
⑤ Karanj (Pongamia Glabra Vent)
The research showed that in most African countries, South Asia, the warm regions of America, and northern areas, the twigs and roots of the above-mentioned plants are used for cleaning the teeth and mouth.
Miswak or peelu was found to be overall effective against bacteria obtained from saliva, and its anti-microbial, germicidal, and fungicidal effects were found to be superior to all other plants. (Medical and General Physiology)

◈ Shah Waliullah Dehlawi rahimahullah says:
“That is, regarding the statement of the Messenger of Allah sallallahu alayhi wa sallam: ‘If I did not consider it difficult for my ummah, I would have commanded them to use the tooth-stick for every prayer,’ I say that its meaning is that if there was no fear of hardship, he would have made the use of the tooth-stick a condition for the validity of prayer, just like ablution (wudu). And there are many such ahadith which clearly indicate that the ijtihad (independent reasoning) of the Prophet sallallahu alayhi wa sallam has a role within the limits of the Shari‘ah. ① And the limits of the Shari‘ah are based on objectives, and removing hardship from the ummah is among those principles upon which the rulings of the Shari‘ah are based... It is appropriate for a person to thoroughly use the tooth-stick inside the mouth, remove the phlegm from the throat and chest, and by using the tooth-stick well inside the mouth, the disease of mouth ulcers is removed and the voice becomes clear.” [حجة الله البالغة ج1 ص183]

6. Commentary:

While referencing al-Sharh al-Kabir, Allamah Ibn al-Mulqin rahimahullah, after the last hadith regarding the miswak, states that the author has mentioned more than one hundred ahadith on this issue, and this is a very large number. Then he says: This is astonishing, that so many ahadith have been transmitted regarding a single Sunnah, while many people, in fact most jurists, neglect this Sunnah. See: [البدر المنیر : 223/3]

Although this number includes both authentic and weak ahadith, the importance of this great Sunnah is made absolutely clear by them.