The scholars have spoken regarding the authenticity of attributing the epistle of al-Iṣṭakhrī to Imam Aḥmad, may Allah have mercy on him.

• Ibn Taymiyya, may Allah have mercy on him, said in Al-Istiqāma (1/73): This creed is not established from Imam Aḥmad in its wording, for I have examined three dark chains of transmission for it containing unknown men. The wordings are the wordings of Ḥarb b. Ismāʿīl, not the wordings of Imam Aḥmad. Those concerned with gathering the statements of Imam Aḥmad did not mention it, such as Abū Bakr al-Khallāl in the book Al-Sunna, nor others from the Iraqis who are knowledgeable about the book of Aḥmad. Nor was it narrated by those known for transmitting the Imam's statements, especially such a large epistle, even if it gained currency among many of the later scholars!! End quote.

I say: This creed is the creed of Ḥarb b. Ismāʿīl al-Kirmānī, may Allah have mercy on him, which he mentioned in his Masāʾil from Aḥmad, Isḥāq, and others from the Imams of the Sunna whom he met and from whom he took knowledge, as I clarified in my verification of the book Al-Sunna by Ḥarb from these Masāʾil.

This creed has been received with acceptance by the people of the Sunna, and they cited it as evidence in their compilations.

• (1) In Al-Ibāna al-Kubrā (2676), it was said to Abū ʿAbd Allāh [Imam Aḥmad, may Allah have mercy on him]: A man said: I say as God Almighty said: {There is no private conversation of three but that He is the fourth of them}, I say this, and I do not go beyond it to anything else? So Abū ʿAbd Allāh said: This is the speech of the Jahmiyya. They said: How should we say? He said: His knowledge is with them, and the beginning of the verse indicates that it is His knowledge, then he recited: {On the Day God will resurrect them} the verse.