Intention to Break the Fast, Nullify the Fast?
Question:
Does a firm intention to break the fast, without eating or drinking cause the fasting person to break his fast?
Answer:
It is well known that fasting is a combination of intention and abandoning, for a person makes the intention by fasting to draw near to Allaah, the Almighty, the All-Powerful by abandoning the things which break the fast. So, if he makes a firm intention to stop it, then the fasting is invalidated; but if it is in Ramadan, he must refrain from eating, drinking and sexual intercourse until the sun sets, because every person who breaks his fast in Ramadan without an excuse is obliged to continue fasting and to make up for it.
However, if he did not make a firm intention, but was undecided, then it is the subject of disagreement among the scholars: some of them say that his fast is invalidated, because indecisiveness invalidates a firm intention. Others hold that it is not invalidated, because the basic principle is that the intention remains valid until such time as he makes a firm intention to break it and end it and this is the more correct view in my opinion as it is more weighty. And Allaah knows best.
Shaykh Muhammad bin Saalih al-`Uthaymeen
Fatawa Arkaanul-Islaam, DARUSSALAM, vol.2, p.646