Know that this subject is very extensive. Many different authentic hadiths have been narrated about it. There are numerous subsidiary discussions in the books of jurisprudence, so we will discuss the basics and the objectives without discussing details or uncommon rulings. I have omitted most of the evidence for the sake of brevity, because this book has not been composed to explain the evidence but merely to explain what should be practiced. And it is Allah 
who grants ability and success.
who grants ability and success.