Musannaf Ibn Abi Shayba 3:1847

4224. Abd al-A’la narrated to us, from al-Jurayri, from Abu al-Ala, from Mutarrif, who said: I asked him about a man who is in doubt regarding the prostration (sajdah): did he hear it or did he not hear it? He said: "And if he heard it, then what?" Then Mutarrif said: I asked Imran ibn Husayn about a man who does not know whether he heard the prostration or not. He said: "And if he heard it, then what?"