Musnad Ahmad 1259:1

Yazid ibn Harun narrated to us, he said: Sa'id informed us, from Qatadah, that Salih—meaning Abu al-Khalil—narrated to him, from Abdullah ibn al-Harith ibn Nawfal, that Umm Hakim bint al-Zubayr narrated to him: "That the Prophet of Allah, may Allah bless him and grant him peace, entered upon Duba'ah bint al-Zubayr. He then took a bite from a shoulder [of meat] that was with her, then he prayed and did not perform ablution from that."