Al-Idâfah

Al-Idâfah means:Association of an ism with another one, in order to affect its definition or to specify its meaning.

Al-Idâfah consists of two words following eachother, the first one is called mudâf and the other one is called mudâf ilayh. Their fields of use include (but is not limited to):

In order to show that one thing is owned by another
In order to make two words get a relation by being placed side-by-side, affecting their meaning. For example: "Keyboard", or "Doorknob"

Example of an idâfah:

"The book of Bilâl"

Specifications for

Mudâf does neither carry tanwîn nor alif lâm at-ta´reef.
Mudâf ilayh is always majroor.

Examples:

"The soorah of sincerity" (a chapter of the qur'an is called a soorah)

"The women's soorah"

So mudâf ilayh is majroor, but why does mudâf always seem to be marfoo`?Because the fundamental rule for asmâ' is that they are marfoo`. In the following example the word "umm" is mudâf to "bilâl" though majroor - because it's mudâf ilayh to "bayt" at the same time:

"Bilâls mothers house"

We say that mudâf is "ism nakirah" due to its lack of

, but when looking at the actual meaning it should be considered ma`rifah if its mudâf ilayh is ma`rifah.

As a similtude in english, we may say "The book", "Your book", and "A computer's book".
The book is considered definite in the first two sentences, in the first because of "the", and in the second one because it is owned by "your" (which is definite), even though it lacks "the". In the third sentence "book" is indefinite due to "a computer" being indefinite.

"This is a page of a book"

"This is the page of the book"