Sa'd narrated from Musa ibn Ja'far ibn Abi Ja'far from Muhammad ibn Abdul-Jabbar from Maymun from Muhammad ibn Al-Faraj who said: I wrote to the Righteous servant (Abd al Salih عليه السلام), peace be upon him, asking Imam عليه السلام about some matters. Imam عليه السلام wrote back to me: "Pray after Asr from the supererogatory prayers as much as you wish, and pray after Fajr from the supererogatory prayers as much as you wish."