Musnad Ahmad 572:12

Muhammad ibn Salamah al-Harrani narrated to us, from Ibn Ishaq—meaning Muhammad—from Ubaydullah, or Abdullah ibn Talhah ibn Kurayz, from al-Hasan, who said: Uthman ibn Abi al-As was invited to a circumcision [feast], but he refused to accept. It was said to him [regarding that], and he said: "We used not to attend circumcision [feasts] during the time of the Messenger of Allah, may Allah bless him and grant him peace, nor were we invited to them."