Imam al-Sadiq (AS) said to Mufadhaal b. Salih, ‘Verily Allah has servants who sincerely engage in transaction with Him in secrecy, so Allah gives them from His pure reward and goodness, for they are the ones who will come on the Day of Resurrection with their book of deeds empty, and when they stand in front of Allah, their books will be filled with the secrets that they had with Him. [Mufadhal narrates], I asked, ‘O my master, why will their books be empty? The Imam replied, ‘Allah holds them in such high regard that He does not even want the guardian angels to be aware of what is between Him and them.