[Al-Būshanjī:] In ’27 [842], Aḥmad ibn Ḥanbal taught Hadith openly in Baghdad. That was right after al-Muʿtaṣim died. We were in Kufa when we heard the news. I headed back to Baghdad and caught up with him in Rajab of that year, while he was still teaching. Then, with three days left in Shaʿbān, he stopped of his own accord. The authorities hadn’t told him to stop, but al-Ḥasan ibn ʿAlī ibn al-Jaʿd, who was then judge in Baghdad, had written to Ibn Abī Duʾād to tell him that Aḥmad was openly teaching Hadith. When Aḥmad learned of this, he stopped without having to be asked.

As far as we know, he had not taught during al-Muʿtaṣim’s reign, which lasted for eight years and eight days. After that he did not teach again at all until he died. 71.1