Why is the Static keyword before a function signature

Question

Possible duplicate:
Why should C # load be static?

Why is the static keyword in front of the function signature of all overloaded operators in C #, for example:

public static void operator = (Object a, Object b)

When we do a = b; then the value will be implicitly passed correctly. Thus, no static keyword is required. It should be like:

public void operator = (Object b)

It?

Answer 1

, , , . , . ( , , ... .)

( , # .)

Answer 2

. a b, .