Musnad Ahmad 32:1342

Rawh narrated to us, Shu'bah narrated to us, he said: I heard Hisham ibn Zayd, he said: I heard Anas ibn Malik narrating that a Jewish woman placed poison in meat, then she brought it to the Messenger of Allah, may Allah bless him and grant him peace, and the Messenger of Allah, may Allah bless him and grant him peace, ate from it. He said: "She has placed poison in it." They said: "O Messenger of Allah, shall we not kill her?" He said: "No." He said: So I continued to recognize that [the effect of the poison] in the uvula of the Messenger of Allah, may Allah bless him and grant him peace.