The Intention of Fasting
An-Niyyah is in the Heart: The Prophet (sallallahu alaihi wa-sallam) said, “The actions are Innama (only, certainty) tied to the intentions and every person will earn that which he intended.” [Agreed upon] An-Niyyah is the resolution (intention) of the heart. The place of the intention is the heart and announcing the Niyyah aloud is an innovation (Bidah) that has no basis in the Book and the Sunnah.
An-Niyyah for the Fard (obligatory) Fasts: It is obligatory to have the intention for the obligatory fasts prior to the dawn (sunrise) as the Prophet (sallallahu alaihi wa-sallam) said, “He, who does not resolve to fast before it is Fajr, then there is no fast for him” [Reported by Abu Dawood (no. 2454). Ibn Khuzaimah (no. 933), al-Baihaqee (4/202), an-Nisaee (4/196) and at Tirmidhee (no. 730). Its isnad is saheeh.]
An-Niyyah for the Nafl (voluntary) Fasts: One may intend to fast voluntarily even after the crack of dawn, unlike the obligatory fasts, provided that one has avoided eating, drinking, and sexual intercourse. Evidence for this ruling is the Hadeeth of Aisha (radhi allahu anha), when she narrated, “The Prophet (sallallahu alaihi wa-sallam) came to visit me one day and asked, ‘Do you have anything (to eat)?’ I said, ‘No.’ He replied, ‘Then, I am fasting.” [Saheeh Muslim]
There is No Specific Dua for an-Niyyah.
“If it crosses a person’s mind that he is going to fast tomorrow, then he has made the intention.” Shaykh al-Islam Ibn Taymiyah in al-Ikhtiyaaraat (p. 191)
“Some scholars were of the view that in the case of a repeated act of worship, it is sufficient to form the intention once the first time one does, unless the sequence of repetition is interrupted, in which case a new intention must be formed. On this basis, if a person has the intention of fasting on the first day of Ramadaan that he will fast this whole month, that is enough to cover the whole month, so long as he does not have an excuse to break his fast and thus break this continuity, such as traveling during Ramadaan. In that case, when he wants to resume fasting he must form the intention of fasting again. This is the more correct opinion, because all the Muslims, if you ask them, will say that they intend to fast the whole month from beginning to the end. So, even if the intention is not formed literally, it is there by implication, because the basic principle is that it does not stop. Hence, we say that if the continuity is broken for some permissible reason, then one starts fasting again, the intention must be renewed. This is the view which brings peace of mind.” Al-Sharh al-Mumti’, vol. 6, p. 369-370.
They Found Out During the Day that Ramadan had Begun, so they Fasted
Question: Some of our Muslim brothers did not know that Ramadaan had begun until after the sun had risen, but they completed their fast. Is that sufficient or do they have to repeat their fast?
Answer: Al-Hamdulillah. They have done the right thing by refraining from eating, etc. for the rest of the day, but they have to fast another day in its place.
The reason why they have to make up the fast is that they did not have the intention of fasting from the night before. The Prophet (sallallahu alaihi wa-sallam) said, ‘Whoever does not make the intention before dawn, there is no fast for him.’ [Narrated by Ahmad (6/287), Abu Dawood (no. 2454), at-Tirmidhee (730), an-Nisaee (2331) classed as saheeh by Shaikh al-Albanee in Saheeh Abu Dawood (2143)] Standing Committee for Academic Research and Issuing Fatawa (10/245)