he utters this word only with the intention of supplication...

he utters this word only with the intention of supplication, or by mistake, or by way of taqayyah his prayers does not become void. Fifth: The fifth thing which nullifies prayers is that a person keeps his back whether intentionally or by mistake, towards Qibla or may move towards the right or left side of Qibla.

In fact if he intentionally turns from the direction of Qibla to such an extent that the people do not say that he is facing Qibla his prayers will become void even though he may not turn fully towards the right or the left side. 1140. If a person turns his head intentionally, or by mistake to such an extent that he faces the right or left side of Qibla or turns more than that his prayers is void.

However, if he turns his head only a little so that the people do not say that he has turned his face from Qibla - whether he does so intentionally or by mistake - his prayers is not nullified. And it he turns his head so much that people may say that he has turned his face from Qibla but does not reach the right or left limit of Qibla his prayers will be void if he has turned his face intentionally, but will be in order if he has turned his face by mistake.

Sixth: The sixth thing, which invalidates prayers, is that one utters a word, consisting of one or more letters, intentionally, though it may carry no meaning. 1141. If a person utters a word consisting of one or more letter by mistake, although that word may carry no meaning his prayers does not become invalid, but it is necessary that after offering the prayers he should perform sajdatus sahu as will be explained later. 1142. There is no harm in coughing, belching or sighing during the prayers.

However, uttering words like 'Oh' or 'Ah' intentionally makes the prayers invalid. 1143. If a person utters a word with the object of recitation e.g. he says Allahu Akbar with that intention and raises his voice while saying it in order to draw another person's attention to something there is no harm in it. Rather, there is no harm if he says something with the intention of recitation, in order to bring something to another person's knowledge. 1144.

There is no harm in reciting the Quran (except the four verses which make prostrations obligatory and which have been mentioned in the orders relating to ceremonial uncleanness (Article 361) and in making supplications during the prayers. However, the recommended precaution is that one should not make supplications in any language except Arabic. 1145.