"The aphorism in which I am the first master among Germans, are the forms of "eternity"; my ambition is to say in ten sentences what everyone else says in a book - what everyone else does not say in a book"

In this quote, Nietzsche is stating that he is the very best at creating aphorisms amongst German authors. He thinks that these aphorisms record the essence of "eternity" and are incredibly powerful. His objective is to condense intricate ideas into just a few sentences, rather than writing a whole book on the subject. He wants to express what others can not say in a book through his concise and effective aphorisms.