Do Sins Break the Fast | Shaykh Aḥmad ibn Yaḥyá al-Najmī Raḥimahullāh
[Q]: Do sins break the fast? And is it mandatory upon the sinner to make up his broken fast due to his sinning?
[A]: Sins vary, and the sins which don’t break the fast reduce the reward of the fasting person. However, there are sins that break the fast, such as masturbation, committing adultery and things similar to that—we ask Allāh for forgiveness and wellbeing. There is absolutely no doubt that those things break the fast.
● [فتاوى الصيام للشيخ أحمد بن يحيى النجمي ص ٣٧]