What is the ruling on changing the intention (*niyyah*) of an established obligatory prayer (*Fard*) to another obligatory prayer?
Chapter on the Description of Prayer
Al-Mughni
Book of Prayer
Primary text
If a person begins an obligatory prayer and then intends to change it to a different obligatory prayer, the first prayer is invalidated because its intention has been cut short. The second prayer is also invalid because the intention for it was not formed at the beginning of the act.
Supporting text
If the intention is changed to a supererogatory prayer (*Nafl*) without a valid reason, the ruling is that it is invalid, according to one narration. Alternatively, it is disliked but valid, as the intention for the supererogatory act can be encompassed within the intention of the obligatory act, evidenced by the case where one begins an obligatory prayer believing its time has not entered, yet it is valid if the time has indeed arrived. If the change to a supererogatory prayer is for a valid reason, such as an individual starting a prayer who then joins a congregation and changes it to a supererogatory prayer to perform his obligatory prayer in congregation, then it is valid without dislike in one opinion. Another opinion holds that it is invalid because the intention for the supererogatory act was not present from the start. A third view permits it because it serves a benefit, which is achieving the reward of congregational prayer, unlike changing it for no reason, which invalidates the deed without benefit.