Islamic Interpretation of Dreams (Ibn-i Sirin):

(Quicksilver) In a dream, mercury means a project, or an intention that will not be brought to completion.

If one sees himself giving mercury to someone, or if he holds it in his hand in a dream, it means that he fails his promises.

It also means that he disinclines in his religious practices, follows his own mind and desire, or it could mean that he is a hoax, a betraying person, or a treacherous person.

Ifhe eats it in a dream, it means that one of his children will grow to be one who fails his promises.