Acts That Do Not Break the Fast and Makrūh Actions Every Fasting Muslim Should Avoid

3. Fast will not be invalid in case of feeling the coolness of the water inside the body after taking bath. (Fatāwā 'Ālamgīrī, pp. 230, vol. 1)
4. 
   If one rinses the mouth with water and spits the water out completely, just a little wetness has remained inside the mouth; swallowing this wetness with saliva will not invalidate the fast. (Rad-dul-Muḥtār, pp. 367, vol. 3)
5. The fast will not be invalid even if the taste of the medicine being crushed is felt in the throat. (ibid)
6. The fast will not be invalid if water enters the ear or even if one pours it deliberately. (Durr-e-Mukhtār, pp. 367, vol. 3)
7. Inserting a splinter into the ear to itch does not invalidate the fast. Even if the splinter comes into contact with ear-dirt and this act is repeatedly done, the fast will not become invalid. (ibid)

8.      If a tiny particle was in the mouth or was stuck between the teeth and it goes down the throat with saliva, the fast will not become invalid. (ibid)

9.      If the gums bleed and the blood reaches the throat but does not go down the throat, fast will not be invalid in this case. (Fatḥ-ul-Qadīr, pp. 258, vol. 2)

10.  Swallowing a fly unintentionally will not invalidate the fast but swallowing it deliberately will invalidate the fast. (Fatāwā 'Ālamgīrī, pp. 203, vol. 1)

11.  If somebody eats food or drinks water forgetfully, but he spits out the food or water from mouth as soon as he recalls the fast, then his fast will not become invalid, but if he swallows the morsel of food or water that was in his mouth despite recalling the fast, the fast will become invalid. (ibid)

12.  If a person who was eating before dawn spits out everything in his mouth as soon as the time of Saharī ends, his fast will not be invalid but if he swallows the food etc. that was in his mouth, his fast will be invalid. (Fatāwā 'Ālamgīrī, pp. 203, vol. 1)

13.  Backbiting does not invalidate the fast. (Durr-e-Mukhtār, pp. 362, vol. 3) However, backbiting is a major sin. The Holy Quran refers to backbiting as 'eating one's dead brother's flesh' and a Hadīš states that 'backbiting is worse than even fornication.' (Aẖtargīb Wattarhīb, pp. 331, vol. 3, Hadīš 24) Backbiting removes the blessings of the fast. (Bahār-e-Sharī'at, pp. 611, part 5)

14.  Being in the state of major impurity (when taking ritual bath is obligatory) or even spending the whole day in this impure state will not invalidate the fast. (Durr-e-Mukhtār, pp. 372, vol. 3) However, remaining in this state deliberately and missing Ṣalāh is a sin and Ḥarām. A Hadīš states that the angels of mercy do not enter the house in which there is a 'Junub' (the one who is in the state of major impurity). (Bahār-e-Sharī'at, pp. 116, part 5)

15.  If one chews a sesame seed or a tiny particle equal to a sesame seed in size which then goes down the throat with saliva, his fast will not be invalid, however, the fast will be invalid if its taste is felt in the throat. (Fatḥ-ul-Qadīr, pp. 259, vol. 2)

16.  Swallowing saliva or phlegm of the mouth will not invalidate the fast. (Rad-dul-Muḥtār, pp. 373, vol. 3)

17.  Swallowing the dried mucus of the nose by inhaling will not invalidate the fast. (ibid)

Makrūh acts in fasting

Let's have a look at the Makrūh acts of fast. Though the fast does not become invalid in case of committing these unpleasant acts, they affect the spirituality of the fast. Here are three blessed Aḥādīš in this regard.

1. Sayyidunā Abū Hurairah رَضِیَ اللّٰهُ تَعَالٰى عَنْهُ has narrated that the Beloved and Blessed Prophet صَلَّى اللّٰهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم has said, 'If someone doesn't avoid indecent speech and acts, Allah عَزَّوَجَلَّ doesn't need such a person as he has just left eating and drinking.' (Ṣaḥīḥ Bukhārī, pp. 628, vol. 1, Hadīš 1903)
2. Sayyidunā Abū Hurairah رَضِیَ اللّٰهُ تَعَالٰى عَنْهُ has reported that the Prophet of Raḥmah, the Intercessor of Ummah صَلَّى اللّٰهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم has said, 'The fast is like a shield unless it is torn.' He صَلَّى اللّٰهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم was asked as to how the shield is torn, he replied 'By lying or backbiting.' (Attargīb Wattarhīb, pp. 94, vol. 2, Hadīš 3)
3. Sayyidunā 'Āmir Bin Rabī'ah رَضِیَ اللّٰهُ عَنْهُمَا has said, 'I have repeatedly seen the Holy Prophet صَلَّى اللّٰهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم use a Miswāk in the state of fast.' (Jāmi' Tirmiżī, pp. 176, vol. 2, Hadīš 725)

Twelve points about Makrūh acts in fasts

1. Lying, telling tales, backbiting, unlawful use of eyes, abusing, hurting someone without the permission of Sharī'ah, shaving beard etc. are all already prohibited and Ḥarām acts and committing them in the state of fast is even more severely Ḥarām. These sins remove the spirituality of the fast.
2. It is Makrūh for a fasting person to unnecessarily taste or chew any thing.

Tasting food to make sure that salt has been mixed into food in required quantity is a valid exemption for a wife whose ill tempered husband gets annoyed if the food is not to his liking. There is no harm for her in tasting food in this case. Chewing food to make it soft (and edible) for her child is a valid exemption for a mother whose child cannot eat bread and she doesn't have any other soft food to feed the child. She can chew food in this case provided there's no such woman who is experiencing her menses or post natal bleeding¹ or anyone else who can chew the food for the child. Therefore, chewing food to make it soft for a child is not Makrūh for her. However, one must be extremely careful when tasting or chewing food (even for valid reasons) because if one swallows even a small amount, the fast will become invalid. (Durr-e-Mukhtār, pp. 395, vol. 3)