مسائل المنتخبه (Articles Of Islamic Acts) - الخوئي، السيد أبوالقاسم - الصفحة ٢٥٣ - BREAKING THE OBLIGATORY PRAYERS

nullified. However, increase in Takbiratul Ehram by mistake does not nullify the prayers.
١١٦٥. If a person doubts, after having performed his prayers, whether or not he performed, while offering prayers, an act, which nullifies prayers, his prayers is in order.

THINGS WHICH ARE ABOMINABLE IN PRAYERS
١١٦٦. It is abominable that a person offering prayers turns his face towards right or left to a small extent so that people do not say that he has turned his facefrom Qibla. Otherwise (i.e. if he turns his face more than that) his prayers will be nullified, as mentioned above. It is also abominable during prayers to shut the eyes orturn them towards right or left, or put the fingers of one hand into those of the other, or play with the beard or hands, or spit, or look at the writing of the holy Quran,or some other book or a ring. It is also abominable during prayers to become silent while reciting Surah al-Hamd or any other surah or zikr (recital) in order to hearsomebody talking. And in bet every such act which disturbs attention and humility is abominable.
١١٦٧. It is abominable for a person to offer players when he is feeling drowsy or is controlling his faeces or urine. Similarly it is abominable to offer prayerswith tight socks which press the feet rigidly. There are other things also which are abominable to do while one is offering prayers. They are mentioned in detailed books onthe subject.

BREAKING THE OBLIGATORY PRAYERS
١١٦٨. It is unlawful to break obligatory prayers purposely. There is, however, no harm in breaking it in order to protect ones property or to escape from financial or corporeal harm.
١١٦٩. If it is not possible for a person to protect, without breaking the prayers. his own life, or the life of a person whose