If someone prayed without facing the Qiblah after making a sincere effort to determine its direction, their prayer is valid, and they do not need to repeat it. However, if they were negligent or failed to make a reasonable effort, they must repeat those prayers in the correct order, as best as they can.

The one who has prayed without purifying himself has to repent and seek forgiveness, and resolve not to do such a thing again. Allah accepts the repentance of those who repent to Him. However, he does not have to enter Islam anew. Additionally, he should repeat the prayer that he offered without purifying himself.

If the Muslim is in a place where he cannot determine the direction of the Qiblah, then he should pray facing the direction which he thinks is most likely to be the direction of the Qiblah, and he does not have to repeat the prayer after that. Rather his prayer is valid but he does not have to do anything else.

If delaying the prayer means that one will miss out on praying in congregation and will pray it alone at the end of its time, then it is prohibited because it means not praying in congregation so long as one does not have an excuse for not praying in congregation.

The regular sunnah prayers that are offered before an obligatory prayer must be done after the time for the obligatory prayer begins.

Praying in cars, planes, trains or other means of conveyance, is not permissible unless there should be the fear that the time for the obligatory prayer will end before reaching your destination and it should not be possible to get off and pray on the ground.

1- Prophet Muhammad forbade praying in seven places: garbage dumps, slaughterhouses, graveyards, the middle of the road, bathrooms, camel pens and on top of the Ka`bah. But this Hadith is inauthentic. 2- It is not valid to quote an inauthentic Hadith to prove that it is not allowed to pray in these places. However, some of these places are mentioned in a sound Hadith: “All the earth is a place of prostration, apart from graveyards and bathrooms.”

If a Muslim man or woman prays in a garment on which there is some impurity, regardless of the type of garment, and he did not remember that until after he had finished praying, then his prayer is valid according to the correct opinion.