Musannaf Ibn Abi Shayba 1:526

Hatim ibn Isma'il narrated to us, from Ja'far, from his father, from Ali ibn al-Husayn or Husayn ibn Ali, from Zaynab bint Umm Salama, who said: The Messenger of Allah (may Allah bless him and grant him peace) was brought a shoulder of a sheep, so he ate from it, then he prayed and did not touch water.