How did the ordeal of the creation of the Qur'an end?

Al-Dhahabi narrates the story of a debate between Ibn Abi Du'ad and one of the Sunnah's shaykhs in the presence of Al-Wathiq, where the shaykh silenced Ibn Abi Du'ad and refuted his assertion of the Quran's createdness. The narration mentions that the shaykh asked Ibn Abi Du'ad: "Did the Prophet, peace and blessings be upon him, and the Rightly Guided Caliphs know about the saying of the Quran's createdness, or did they not know about it?" Ibn Abi Du'ad remained silent, and when he finally replied that they knew about it but did not call people to it, the shaykh asked him: "Could not what sufficed them suffice you?" This affected Al-Wathiq, who then ordered the release of the shaykh and gave him money, and Ibn Abi Du'ad fell from his regard.