If you are eating at suhoor and it's time to stop are you supposed to rinse your mouth out and even brush one's teeth to get rid of any food particles? The concern is swallowing food particles already in the mouth after fasting has begun - would it break the fast? Further if you are already in wudhu (ready for Fajr) and so there is no need to do wudhu again, then do you still need to rinse the mouth / brush teeth? (Because if you needed to do wudhu one of acts is brushing teeth / mouth rinsing). Please clarify.
Are you supposed to rinse your mouth out and brush your teeth after suhoor?
No, you are not obliged to rinse your mouth or brush your teeth after suhoor. However, it is best for someone to rinse his mouth and/or brush his teeth to remove any food left in his mouth.
Is swallowing food particles already in the mouth after fasting has begun break the fast?
Swallowing bits of food that may be left between the teeth is regarded as eating, so it invalidates the fast.
This applies if the fasting person swallows it by choice, and is able to expel it but he swallows it deliberately. But if it has already reached his throat and he swallows it and cannot expel it, then there is no sin on him and his fast remains valid, because in all cases where a thing invalidates the fast, that is conditional upon the fasting person doing it by choice. If he does it by force or involuntarily, then his fast is valid and there is no sin on him.
Ibn Qudaamah said:
If a person has food between his teeth, one of the following two scenarios must apply:
1 – It is a small amount that he cannot spit out, so he swallows it. This does not invalidate his fast, because it cannot be avoided. It is like saliva.
2 – It is a large amount and he can spit it out. If he spits it out there is no sin on him, but if he swallows it deliberately, his fast is invalidated according to the majority of scholars, because he has swallowed food that he could have spat out willingly when he is mindful of his fast. So this breaks the fast just as if he deliberately started eating.
If you are already in wudhu (ready for Fajr) and so there is no need to do wudhu again, then do you still need to rinse the mouth / brush teeth after eating?
If you are in wudhu and you ate something that doesn't break your wudhu like camel meat, it is mustahab to clean your mouth (by rinsing, brushing or using a miswak) before praying. But if you don't do so, then nothing is on you and your prayer is valid.
Sheikh Abd al-Aziz ibn Baz was asked:
Question - After performing Wudhu, I ate some food. Must I do madmadah (rinsing the mouth) to remove the food remnants before performing the obligatory Salah?
Answer - Doing madmadah is mustahab (desirable) to get rid off food remnants. There is no harm if these remnants are not removed. Yet, if you eat camel meat, you must perform Wudhu before offering Salah because this kind of meat nullified Wudhu.