I used to write down everything I hear from the Messenger of Allah and I want to memorize. But the Quraysh advised me against it. They said: You write down everything you hear from the Messenger of Allah, and he speaks in contentment and anger. He said: So I stopped, then I mentioned that to the Prophet (PBUH). He pointed with his hand to his mouth and said: Write, for by the One in whose hand is my self, nothing comes out of it except the truth.