The meaning of the killer that does not die

1. We were told by my father, may Allah grant him mercy, that he said: We were told by Sa’d bin Abdullah, from Ahmad bin Muhammed bin Isa, from Hussain bin Sa’eed, from Muhammed bin Abi ‘Umayr, from Mansur bin Yunus, from Abu Hamza al-Thumali, from Ali bin Hussain, peace be upon them both, that he said: The Messenger of Allah, Allah’s blessings be upon him and his Family, said