Musannaf Ibn Abi Shayba 3:3026

Husayn ibn Ali narrated to us, from al-Hasan ibn Abjar, from Maymun ibn Abi Shabib, who said: I intended to attend the Friday prayer during the time of al-Hajjaj. I prepared myself to go, then I said: "Where am I going? Shall I pray behind this [man]?" He said: I said one time, "I will go," and another time, "I will not go." He said: Then my opinion settled on going. He said: A caller called out to me from the side of the house: "O you who have believed, when [the adhan] is called for the prayer on the day of Jumu'ah [Friday], then proceed to the remembrance of Allah." He said: And I sat one time writing a book, and something occurred to me that if I wrote it in my book, it would adorn my book, but I would have lied; and if I left it out, there would be some ugliness in my book, but I would have been truthful. I said one time, "I will write it," and I said another time, "I will not write it." He said: Then my opinion settled on leaving it, so I left it. He said: A caller called out to me from the side of the house: "Allah keeps firm those who believe, with the firm word, in the worldly life and in the Hereafter."