Musannaf Ibn Abi Shayba 17:1352

Abu Usama narrated to us, from Mujalid, who said: Amir informed us, saying: A man said in the presence of al-Mughira ibn Shu'ba: "May Allah send blessings upon Muhammad, the Seal of the Prophets, there is no prophet after him." Al-Mughira said: "That is sufficient for you. When you have said 'the Seal of the Prophets,' [that is enough], for we used to be told that Isa (Jesus) will emerge. If he emerges, then he was before him and after him."