مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3755
Musnad of Abdullah bin Mas'ood
It was narrated that Ibn Mas'ood (رضي الله عنه) said: Some eloquence is magic. We used to think that the Messenger of Allah (ﷺ) had been poisoned with poison put in the foreleg of a sheep, that the Jews had poisoned.
Musnad Ahmad 3778Its isnad is da’eef]