Musannaf Ibn Abi Shayba 3:5618

Abu Bakr narrated to us, he said: Ibn ‘Uyaynah narrated to us, from al-Zuhri, from ‘Abbad ibn Tamim, from his uncle, who said: A man complained to the Prophet, peace and blessings of Allah be upon him, about a man who finds something during prayer and is in doubt about it. He said: "Nothing is incumbent upon him until he finds its scent or hears its sound."