Pillars & FiqhZakat is the third pillar of Islam; it is an obligatory due on specified wealth, paid to those entitled to it from the eight categories. It becomes obligatory on wealth when it reaches the nisab (minimum threshold) and a full lunar year has passed over it. It is a purification of wealth and an increase in blessing.
Source:حديث جبريل، رواه مسلم؛ والبقرة: 43

