Umar bin Muhammad bin al-Mnkdr عمر بن محمد بن المنكدر · The Book of Jihad

: “When the Messenger of Allah died and Abu Bakr was appointed as Khalifah, and some of the Arab’s disbelieved, Umar said: ‘O Abu Bakr! How can you fight the people when the Messenger of Allah said: I have been commanded to fight the people until they say La ilaha illallah (there is none worthy of worship except Allah). Whoever says La ilaha illallah, his life and his property are safe from me, except for its right, and his reckoning…