Reference: Fataawa Ramadhaan – Volume 2, Page 751, Fatwa No.763
Fiqh al-Ibaadaat libni ‘Uthaymeen – Page 178-179
Question: We need to know the ruling about the fast of one who does not pray [the obligatory prayers]?
Response: One who does not pray, [then] his fast is not correct and it is not acceptable from him. This is because the one who does not pray is a disbeliever and apostate (murtad), as Allaah (subhaanahu wa ta’aala) says:
And also the statement of the Prophet (sal-Allaahu ‘alayhi wa sallam):
…and also His (sal-Allaahu ‘alayhi wa sallam) saying:
And certainly this is the statement of the general Companions, if it is not a concensus amongst them. ‘Abdullaah Ibn Shaqeeq (rahimahullaah) who was amongst the prominent Taabi’oon said: “The Companions of the Prophet (sal-Allaahu ‘alayhi wa sallam) did not see the leaving off of any actions to be kufr (disbelief) except the prayer”. And based upon this, if a person was to fast whilst he did not pray, then his fast is rejected and unacceptable and there is no benefit for him in front of Allaah on the Day of Judgement. And we say to him: Pray then fast, as for fasting and not praying then your fast is rejected because [any] act of worship is not acceptable from a disbeliever.