Benefit: Fasting in Ramaḍān Whilst Leaving Off the Prayers
In the Name of Allāh, the Ever Merciful, the Bestower of Mercy
[A]: The one who fasts while leaving off the prayers, then his fasting will not benefit him. It will not be accepted from him and he has not removed the obligation [of fasting] from himself [i.e. his fasting will not be counted]. Rather, he is not requested to fast as long as he leaves off the prayers because the one who does not establish the prayers is like the Jew or Christian, what if a Jew or Christian fasted, will it be accepted from them? It will not!
So we say to this individual: Repent to Allāh, establish the prayers and fast. Indeed Allāh accepts the repentance of the repentant one.
Shaykh Muḥammad ibn Ṣāliḥ al-ʿUthaymīn
Source: فتاوى في الصيام، الكتاب: ٤٨
Translated by: Munīb al-Ṣumālī