Everything in this book that is narrated from what Imam Al-Ridha (as) wrote to Muhammad ibn Sinan in response to his questions on causes has been transmitted by me from Ali ibn Ahmad ibn Musa Al-Daqqaq, Muhammad ibn Ahmad Al-Sinani, and Al-Husayn ibn Ibrahim ibn Ahmad ibn Hisham Al-Maktab - may Allah (swt) be pleased with them all - who said
Muhammad ibn Abi Abdullah Al-Kufi narrated to us, who said: Muhammad ibn Isma'il Al-Barmaki narrated to us, from Ali ibn Al-Abbas, who said: Al-Qasim ibn Al-Rabi' Al-Sahhaf narrated to us, from Muhammad ibn Sinan, from Imam Al-Ridha (as).