Definition Of Siyaam (fasting)
(1) Siyaam in Arabic means abstaining; in Islam it means abstaining from things that break the fast, from dawn until sunset, having first made the intention (niyyah) to fast.
Ruling on fasting.
(2) The ummah is agreed that fasting the month of Ramadaan is obligatory, the evidence for which is in the Qur’aan and Sunnah. Allaah says (interpretation of the meaning):