Musannaf Ibn Abi Shayba 1:1104

Al-Thaqafi narrated to us, from Ayyub, from Muhammad, that Umar relieved himself, then began to recite [the Quran]. Abu Maryam said to him, "If you were to perform ablution, O Commander of the Faithful." Umar said to him, "Did Musaylimah give you that fatwa?"