Foundational
Issue No.863- Some of the obligatory acts of prayer are foundational elements (rukn). Hence, a person who does not offer them or adds an undue one, whether intentionally or by mistake, his prayer becomes void. Some other obligatory acts of prayer are not foundational elements. Meaning, if they are omitted or added intentionally, the prayer becomes void but if this happens out of oversight or mistake, the prayer would be correct.
