Imam Malik {May Allah have Mercy upon him} said:
I know many sayings of the Prophet {Peace and Blessings of Allah be upon him} and had a great deal of knowledge that I never spoke about nor did I even mention it. And that was the knowledge of the heart.
{Kitab al-Muwafaqat fi Usul as-Shariah ~ The Reconciliation of the Fundamentals of Islamic Law, 4/36}
