Musannaf Ibn Abi Shayba 23:169

Ibn ‘Ulayyah narrated to us, from Yunus, from al-Hasan, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "I saw in my hands two bracelets of gold, so I disliked them. Then I blew upon them, and they departed: Chosroes and Caesar."