He said: Al-Sharif al-Swaleh Abu Muhammad b. Hamza al-Alawi al-Husaini al-Tabari, may ALLAH (SWT) bless him with mercy, reported to me from Muhammad b. Abdillah b. Ja'far al-Himyari, from his father, from Ahmad b. Muhammad b. Isa, from Murook b. Ubaid al-Kufi, from Muhammad b. Zaid al-Tabari, who said:
I was present at the residence of al-Ridha, ALI b. Musa, peace be upon him, at Khurasan, and a group of Banu Hashim, including Ishaq b. al-Abbas b. Musa, was present also. So, addressing Ishaq, (al-Ridha) said: "O Ishaq! I have come to learn that you are telling people that we consider them as our slaves.
I swear by my relation with the MESSENGER of ALLAH (SWT), peace be upon him and his progeny, I have never said that! Nor did I hear to that effect from my forefathers, nor has it been conveyed to me from them through anyone. Yes, what we have said is that people are subservient to us in matters of obedience to ALLAH (SWT), loyal to us in religion. So let those present here convey this to those who are absent."
(Ref: Al-Amali Shaikh Mufeed: The Thirtieth Assembly Hadees No.3)