Answered by Ustadh Tabraze Azam
Question: Assalam ‘aleykum
If someone has eaten onions and enters the mosque without cleaning the teeth is it haram?
Answer: Wa alaikum assalam wa rahmatullahi wa barakatuh,
I pray that you are in the best of health and faith, insha’Allah.
It is disliked to enter the mosque when affected by an unpleasant smell that will irritate, annoy, or harm another person. [Ibn `Abidin, Radd al-Muhtar]
This is what would be considered an unacceptable bad smell. A slightly bad smell on the other hand would be that which doesn’t affect other people. As such, the dislikedness would be less emphatic, though it would remain improper and undignified to enter a mosque or the like in such a state.
Unpleasant and Annoying Smells
The Messenger of Allah (Allah bless him and give him peace) said, “Anyone who eats any of this plant, i.e. garlic, should not come near our mosque.” [Bukhari]
The commentators of this and other similar narrations mention that the prohibition applies to all foul smells which emit from a person whether from food or otherwise. Hence, this ruling would also apply to smoking in all of its forms.
Why the Mosque & Is the Prohibition limited to it?
The reason for the prohibition is twofold. Firstly, that foul smells cause harm and annoyance to the angels as well as fellow believers. And secondly, the mosque is a place of worship and it is highly improper that foul smells are wilfully brought into such a sacred space.
The scholars add that the aforementioned rulings actually extend to any gathering of knowledge, remembrance, or other form of worship.
What should I do if bad smell is affecting me?
It is from the mercy of our tradition to have concern for other people and to uphold the rights due to them.
Thus, if you are affected by an unpleasant smell, you should do your best to reduce it as much as possible by either thoroughly rinsing out your mouth, applying scent to yourself, or even changing your clothing if the smell would be considered unacceptable.
If in doubt, rinsing your mouth should be sufficient. But emitting a bad smell should not be a reason or excuse to skip attending the congregation or gathering.
Tooth sticks (miswak) and Strong Believers
This is actually one of the benefits of having and using the tooth stick (miswak). It is a recommended sunna to use it whenever the odour of your mouth changes as the jurists (fuqaha) mention.
The Messenger of Allah (Allah bless him and give him peace) said, “Brushing one’s teeth cleans the mouth and pleases the Lord.” [Bukhari]
Hence there is much wisdom in carrying it around on your person, namely from following the sunna in the most optimal way to keeping your mouth smelling clean.
“The strong believer is better and more beloved to Allah than the weak believer, although there is good in both. Be avid for all that benefits,” said the Messenger of Allah (Allah bless him and give him peace). The strong believer takes the most effective and beneficial of means in all walks of life.[Nawawi, Sharh Sahih Muslim; `Ayni, `Umdat al-Qari]
And Allah alone gives success.
Checked & Approved by Faraz Rabbani