In Islam, purification is of high esteem to the extent that the Prophet (peace and blessings be upon him) regarded it as a half of one’s iman (faith), saying, “Purification is half of the Faith.”
Meanwhile, Islam calls for beautification and adornment. When going to the mosques, Muslims are recommended to wear the best of their clothes. Allah, Most High, says: “O Children of Adam! wear your beautiful apparel at every time and place of prayer: eat and drink: But waste not by excess, for Allah loveth not the wasters.” (Al-A`raf: 31)
Islam calls upon Muslim to beautify their bodies, clothes, houses, offices, streets, etc. It is reported that the Prophet, peace and blessings be upon him, said, “Cleanse yourself, for Islam calls to cleanliness.” (Reported by ibn Hayyan) He also says, “Cleanliness enhances one’s faith, and faith leads its possessor to the Garden.” (Reported by At-Tabarani)
The Prophet (peace and blessings be upon him) placed a great emphasis on keeping the body, clothing, houses, and streets clean, and he laid special stress on cleaning the teeth, hands, and hair. This emphasis on cleanliness must not be a cause of wonder for a religion which makes cleanliness the key to its main pillar of worship, salah, for the Muslim’s salah is not acceptable unless his body, clothing, and the place where he performs his salah are all clean. In addition to this requirement, there are the obligatory types of cleansing, either of the entire body in the form of ghusl (purificatory bath), or of those parts of the body which are exposed to dirt, in the form of wudu’ (ablution).
Sheikh M. S. Al-Munajjid, a prominent Saudi Islamic lecturer and author, states that: “Siwak means cleaning the mouth with a stick or twig called siwak, from which the act derives its name.
So, the word siwak also refers to a method of cleaning the mouth, which is something that earn one the pleasure of Allah, as it is proven in the hadith of `A’ishah (may Allah be pleased with her) who quotes Allah’s Messenger (peace and blessings be upon him) as saying, “Siwak cleanses the mouth and earns one the Lord’s pleasure.” (Reported by Al-Bukhari)
Use of the siwak is repeatedly encouraged, as in the hadith of Abu Hurayrah (may Allah be pleased with him) who reported that the Prophet (peace and blessings be upon him) said: “Were it not for the fact that I did not want to make things too hard for my Ummah, I would have commanded them to use the siwak at every time of Salah.” (Reported by Al-Bukhari)
According to another report narrated by Al-Bukhari, he said: “… at every time of making wudu’.”
Imam An-Nawawi reported that the respectable scholars agreed that the use of the siwak is Sunnah and is encouraged. One of the signs of its importance is the fact that some of the salaf (early pious Muslims), such as Ishaq ibn Rahawayh, thought that it was obligatory.
Times when use of Siwak is recommended:
Siwak is recommended at all times of night and day, because of the general sense of the hadith
 quoted above from `A’ishah, “Siwak cleanses the teeth and pleases the Lord.” The scholars have also mentioned situations where use of the siwak is even more strongly encouraged; these include:
1. When making wudu’ and at times of salah: The Prophet (peace and blessings be upon him) said: “Were it not for the fact that I did not want to make things too hard for my Ummah, I would have commanded them to use the siwak at every time of salah”, according to another report he said: “… at every time of making wudu’.”
2. When entering one’s home to be with one’s family: `A’ishah was asked what the Messenger of Allah (peace and blessings be upon him) used to do whenever he first arrived home. She said, “Whenever he entered his house, the first thing he would do was to use the siwak.” (Reported by Muslim)
3. When getting up from sleep: Hudhayfah ibn Al-Yaman (may Allah be pleased with him) reported that when the Prophet (peace and blessings be upon him) got up during the night, he would clean his mouth thoroughly with the siwak. (Reported by Al-Bukhari)
4. When the smell of one’s mouth changes, whether this is because of eating food with a strong odor, or because of not eating or drinking for a long time, etc.: Siwak is means of cleansing the mouth, which means that it should definitely be used when the mouth needs cleaning.
5. When going to the mosque: Using siwak is part of the adornment which is greatly recommended for Muslims for every Prayer, as Allah says, “O Children of Adam! Wear your beautiful apparel at every time and place of prayer: eat and drink: But waste not by excess, for Allah loveth not the wasters.” (Al-A`raf:3)
6. When reading the Qur’an and joining gatherings in which Allah is remembered (dhikr) because the angels are present on such occasions.
Using Siwak when fasting:
The Muslim scholars agreed that there is nothing wrong with using siwak during the day when one is fasting, but they differed with regard to using it afternoon, which some of them disliked (makruh). The correct view is that it is Sunnah for one who is fasting, just as it is for anyone else, because of the general sense of the reports which prove that it is Sunnah. The Prophet (peace and blessings be upon him) did not make any exceptions or state any specific time, and a statement that is general in nature should be construed as denoting a general implication unless there is evidence to indicate that it is specific in application.
The hadith quoted as evidence to forbid using siwak afternoon is attributed to `Ali ibn Abi Talib (may Allah be pleased with him) who quotes the Prophet (peace and blessings be upon him) as saying, “When you fast, use siwak in the morning but do not use it in the afternoon.” (Reported by al-Daraqutni) This is a da`if (weak) hadith. There is no proof that this can be attributed to the Prophet (peace and blessings be upon him). With regard to the use of the hadith: “The odor that comes from the mouth of the fasting person is better in the sight of Allah than the scent of musk” (reported by Al-Bukhari and Muslim) as evidence, this mouth odor will not be dispelled by use of siwak because it is caused by having empty stomach, and this could occur early in the day if a person has not eaten suhur. All the scholars are agreed that it is permissible for a fasting person to use siwak early in the day. This shows that use of siwak is encouraged even when fasting, and there is no difference between using it early in the day or later on.
What should be used for Siwak (cleaning the mouth):
The scholars agreed that the best thing for cleaning the mouth is the twigs of the Arak tree, because of its good smell, and because it has brush-like fibers which are effective for cleaning food particles from between the teeth, and because of the hadith of `Abdulallah ibn Mas`ud (may Allah be pleased with him) who said: “I used to gather siwak sticks from the Arak tree for the Messenger of Allah, peace and blessings be upon him.” (Reported by Ahmad)
If Arak twigs are not available, the scholars recommend using palm-leaf stalks, or twigs of the olive tree. The hadiths that have been narrated concerning this, however, are not Sahih (authentic).
The correct view is that any kind of sticks that are good for cleansing and not harmful to teeth may be used instead of the famous siwak, if it is not available, to clean the mouth and remove dirt from the teeth. This includes modern toothbrushes which are known to be beneficial in this regard. However, the scholars have stated that it is forbidden to use poisonous sticks, things that are not tahir (pure), and anything that may cause bleeding, illness or any other harm.
Attributes of Siwak
The Muslim scholars have described the siwak as a stick of medium length and thickness, no thicker than one’s little finger, and free of knots. It should not be so wet that it will twist, because then it will not remove dirt, nor should it be so dry that it will hurt the mouth or crack during use. No doubt this is describing the ideal, otherwise the reports do not specify any particular type of siwak. It is permissible to use any kind of siwak that will do the job.
How to clean the mouth with Siwak:
The scholars have differed as to whether siwak should be done with the right hand or the left hand. One group, the majority of Muslim scholars, think that it is better to use the right hand, because of the general meaning of the hadith narrated by `A’ishah (may Allah be pleased with her) who said: “The Messenger of Allah (peace and blessings be upon him) liked to start with the right when putting on his shoes, dismounting (from his camel), when cleaning himself, and in all things.” (Agreed upon) They also say that siwak is an act of worship that draws one closer to Allah, so it should not be done with the left hand.
Other scholars say that it is better to use the left hand for siwak, because it comes under the heading of removing dirt. This is the well-known opinion of Imam Ahmad’s madhhab (school of fiqh), and it is the view favored by Shaykh Al-Islam ibn Taymiyah (may Allah have mercy on him).
Some scholars have said that when a person uses siwak with the intention of following the Sunnah, he should use his right hand, and if he is doing it to remove dirt, he should use his left hand. The fact of the matter is that this issue is open, as there is no definitive evidence or report, and every opinion has a valid point.
The Muslim scholars suggested that when using siwak, a person should start on the right, and use a side-to-side motion rather than up-and-down, as the latter may harm the gums. Among the etiquette of using siwak, they mentioned the following:
1. A person should not use the siwak in front of others or in public, because this is impolite.
2. The siwak should be washed after use, to get rid of any dirt that may be on it. `A’ishah (may Allah be pleased with her) said: “The Prophet (peace and blessings be upon him) used to use siwak, then he would give it to me to wash it. I would use it first, then wash it and give it back to him.” (Reported by Abu Dawud)
3. The siwak should be kept in a clean place.
Using one’s fingers to clean one’s mouth:
The scholars differ as to whether it is acceptable to use one’s fingers to clean one’s mouth when there is nothing else available. The correct view is that using the fingers cannot be considered as a substitute for the Sunnah action, because there is no basis in Islam for doing so, and this method does not clean the mouth as a siwak or similar instrument does. Modern methods of cleaning the teeth, like toothbru
shes and so on, that remove dirt and make the mouth smell good, are acceptable.
There is nothing wrong with using siwak that is flavored with mint, lemon and so on, so long as they do not cause any harm. But a person who is fasting should avoid using any flavored siwak, and should only use natural siwak when he is fasting.”