Whilst Imaam Ahmad was on the receiving end of being lashed, his lower garment was about to fall, thus expose his awrah. So Al-Mu’tasim ordered for him to be leaved alone for a short while.
At this moment, Ibn Abee Duwaad came to him and said, “O Ahmad, say in my ear ‘The Qur’aan is created’, so that I may save you form the hand of the khaleefah (Al-Mu’tasim)
So Imaam Ahmad said to him, “O Ibn Abee Duwaad, say in my ear, ‘The Qur’aan is the speech of Allaah, it is not created’, so that I may save you from the punishment of Allaah, the Mighty and Majestic.
[The Foundations Of The Sunnah, p. 94]