He had written some books such as “Ilal as-Sawm...

He had written some books such as “Ilal as-Sawm: causes of fasting” and “Masa’il ar-Rijal: questions of men” which he had collected from Abul Hasan the Third (Imam ar-Redha) (a.s.).[^18] Sheikh at-Toosi said he was one from those who had met Imam al-Mahdi (a.s.).[^19] Muhammad bin Ahmed bin as-Salt al-Qummi wrote a letter to ad-Dar (to the imam) and mentioned in it the story of Ahmed bin Isaaq al-Qummi and his companionship.

He mentioned that he wanted to perform Hajj and needed one thousand dinars. He said in the letter, ‘If my master sees that he orders to lend him this amount and get it back from him in his country when he comes back, I shall do it (give him the money).’ The imam (a.s.) replied, ‘It is a gift from us to him and when he comes back, he will get another gift from us.’[^20] This story showed his faith and the respect of the imam (a.s.) towards him.

Abdullah bin Ja’far al-Himyari said, ‘Once, Sheikh Abu Amr (may Allah have mercy on him) and I met Ahmad bin Isaaq, who signaled to me to ask Abu Amr about the Successor (Imam al-Mahdi). I said to him, ‘O Abu Amr, I want to ask you about something that I have no doubt about.’ He said, ‘Ask about what you want!’ I said to him, ‘Did you see the Successor after Abu Muhammad (a.s.)?’ He said, ‘By Allah, yes.’[^21] Anyhow, this man was reliable and had a high position near the Ahlul Bayt (a.s.).

Ahmad bin al-Hasan bin Ali bin Fadhdhal Sheikh at-Toosi mentioned him as one of Imam al-Hadi’s and Imam al-Askari's companions.[^22] It was said that he was Fatahite[^23] and he was reliable in narration. He had written some books such as “Prayer”, and “Wudu”.

He died in 260 AH.[^24] Abu Ali Ahmad bin Hammad al-Mahmudi Sheikh at-Toosi mentioned him as one of Imam al-Hadi and Imam al-Askari's companions.[^25] Al-Kashshi mentioned that Muhammad bin Mas’ood said, ‘Abu Ali Muhammad bin Ahmad bin Hammad al-Mahmudi al-Marwazi said, ‘Abu Ja’far (a.s.) wrote to my father (as mentioned earlier) in a chapter of his book,… (and every soul shall be paid in full what it has earned, and they shall not be wronged) .[^26] As for this life, we are tried in it with misfortunes, but whoever loves his friend and believes in his beliefs shall be with him even if he is far from him.

And as for the afterlife, it is the abode of eternity.’ Al-Mahmudi said, “The imam (a.s.) wrote to me after my father’s death, ‘Your father has passed away, may Allah be pleased with him and with you. He is still praiseworthy to us.