Allah has given a parable: a straight path

The Prophet (may Allah's peace and blessings be upon him) pointed out that Allah Almighty gave a parable likening Islam to a straight extended path that has no crookedness. On the two sides of this path there are two walls surrounding it. These two walls are the limits set by Allah, and within them there are open doors, which are Allah's prohibitions. On these doors, there are curtains that do not allow passersby to see who is inside.

There is a caller at the beginning of this path who directs people and says to them: Walk on this path and do not deviate from it towards the sides. This caller is the Book of Allah. There is another caller above the path. When anyone walking on the path wants to open any of the curtains above these doors a little bit, he forbids him saying: Woe unto you; do not open it! If you open it, you will pass through, and you will not be able to prevent yourself from entering.

This caller is Allah's admonishment in the heart of every Muslim.