In addition to leaving out the obligatory parts, there are other matters that invalidate the prayer. They must be known to be avoided. Among these matters are:
- Saying words other than the words of the prayer intentionally, remembering that one is praying, and knowing that it is forbidden to do so.
- Making many moves for a time that is enough to make one rak^ah.
- Performing an excessive move, such as an excessive jump.
- Adding an extra obligatory action such as making two ruku^s or three sujuds in one rak^ah, on purpose and while remembering that one is praying.
- Making one move with the intention of playing, such as to extend one’s tongue or to wink playfully.
- Eating or drinking, even a small amount while remembering one is praying.
- Invalidating one’s ablution, such as passing gas or urine.
- Intending in the heart to interrupt the prayer. Intending to interrupt it if a specific matter happens, such as if one holds: “If the door bell rings I will interrupt my prayer”, invalidates the prayer immediately.