The Difference Between an Obligation (Fard) and a Pillar (Rukn)

Question:
Yes. May Allah reward you. The questioner says in this question: Is there a difference between a fard (obligation) and a rukn (pillar)? There is no difference between them except that the fard

Answer:
is broader. The fard is broader than the rukn. A fard may be a rukn, or it may be a wajib (obligatory act). As for the rukn, it is what is internal to the act of worship; the rukn is what is internal to the act of worship upon which the act of worship stands, such as the pillars of prayer, the pillars of Islam, and the pillars of faith. These acts of worship stand upon them, and without them, the act of worship is not sound. As for the fard, which is the wajib, it completes the act of worship. Yes.