2. [2/249] al-Kafi: Ali b. Muhammad from Muhammad b. Ali b. Bilal who said: There came to me from Abi Muhammad [al-Askari] عليه السلام [a letter] informing me of the identity of the successor after him two years before his [al-Askari’s] death. Then there came to me [a letter] informing me of the successor after him three days before his death.