If you want to borrow an idea from an author, but do not need his or her exact words, you should try paraphrasing instead of quoting.
Most of the time, paraphrasing and summarizing your sources is sufficient (but remember that you still have to cite them! If you think it’s important to quote something, an excellent rule of thumb is that for every line you quote, you should have at least two lines analyzing it.
Do so following the documentation style recommended by your teacher -- most likely American Psychological Association or Modern Language Association style.
APA, which sets style rules for papers written in the field of social science, refers to quotes with more than 40 words as a block quotation.
Although it stood with its head raised, even its yellowed wings had been eaten by insects.
He thought of his entire life and felt tears and cruel laughter welling up inside. With this gesture Akutagawa ironizes the impossibility of truly writing the self by emphasizing the inevitable split that must occur between writing and written “self,” the Akutagawa still writing “A Fool's Life” cannot possibly be identical with the narrated persona which has finished the work.
To make a substitution this important, however, you had better be sure that [money] is what the final phrase meant -- if the author intentionally left it ambiguous, you would be significantly altering his meaning.
That would make you guilty of fraudulent attribution.
Whenever you change the original words of your source, you must indicate that you have done so.
Otherwise, you would be claiming the original author used words that he or she did not use. You could accidentally change the meaning of the quotation, and falsely claim the author said something they did not.