Reference: Fataawa Ramadhaan v1 p171 no.108
Fataawa as-Siyaam libni Jibreen p37
Question: Is it a must for one who is fasting, that when he makes the intention to fast in Ramadhaan that he specify that it is an obligatory fast?
Response: It is enough for him to make the intention that it is the fast of Ramadhaan and not say “I have made the intention that it is [an] obligatory [fast]”, since it is understood that the fast of Ramadhaan is obligatory.
