narrated that the Messenger of Allah ﷺ said: "I have been ordered to fight the people until they say La Ilaha Illallah", and if they say that, then their blood and wealth will be protected from me, except what it makes obligatory upon them, and their reckoning is up to Allah."  

قَالَ رَسُولُ اللَّهِ ﷺ أُمِرْتُ أَنْ أُقَاتِلَ النَّاسَ حَتَّى يَقُولُوا لاَ إِلَهَ إِلاَّ اللَّهُ فَإِذَا قَالُوهَا مَنَعُوا مِنِّي دِمَاءَهُمْ وَأَمْوَالَهُمْ إِلاَّ بِحَقِّهَا وَحِسَابُهُمْ عَلَى اللَّهِ وَفِي الْبَابِ عَنْ جَابِرٍ وَأَبِي سَعِيدٍ وَابْنِ عُمَرَ  

said: "When the Messenger of Allah ﷺ died and Abu Bakr became the Khalifah after him, whoever disbelieved from the Arabs disbelieved, so Umar bin Al-Khattab said to Abu Bakr: 'How will you fight the people while the Messenger of Allah has said: 'I have been ordered to fight the people until they say La Ilaha Illallah, and if they say that, then their blood and wealth will be protected from me, except what it makes obligatory upon them, and their reckoning is with Allah?' So Abu Bakr said: 'By Allah I will fight whoever differentiates between Salat and Zakat. For indeed, Zakat is the right due upon wealth. And by Allah! If they withhold even (camel) tethers which they used to give to the Messenger of Allah ﷺ I will fight them for withholding it.' So Umar bin Al-Khattab said: 'By Allah! I saw that Allah had opened Abu Bakr's chest to fighting, so I knew that it was correct.'"  

لَمَّا تُوُفِّيَ رَسُولُ اللَّهِ ﷺ وَاسْتُخْلِفَ أَبُو بَكْرٍ بَعْدَهُ كَفَرَ مَنْ كَفَرَ مِنَ الْعَرَبِ فَقَالَ عُمَرُ بْنُ الْخَطَّابِ لأَبِي بَكْرٍ كَيْفَ تُقَاتِلُ النَّاسَ وَقَدْ قَالَ رَسُولُ اللَّهِ ﷺ أُمِرْتُ أَنْ أُقَاتِلَ النَّاسَ حَتَّى يَقُولُوا لاَ إِلَهَ إِلاَّ اللَّهُ وَمَنْ قَالَ لاَ إِلَهَ إِلاَّ اللَّهُ عَصَمَ مِنِّي مَالَهُ وَنَفْسَهُ إِلاَّ بِحَقِّهِ وَحِسَابُهُ عَلَى اللَّهِ قَالَ أَبُو بَكْرٍ وَاللَّهِ لأُقَاتِلَنَّ مَنْ فَرَّقَ بَيْنَ الزَّكَاةِ وَالصَّلاَةِ فَإِنَّ الزَّكَاةَ حَقُّ الْمَالِ وَاللَّهِ لَوْ مَنَعُونِي عِقَالاً كَانُوا يُؤَدُّونَهُ إِلَى رَسُولِ اللَّهِ ﷺ لَقَاتَلْتُهُمْ عَلَى مَنْعِهِ فَقَالَ عُمَرُ بْنُ الْخَطَّابِ فَوَاللَّهِ مَا هُوَ إِلاَّ أَنْ رَأَيْتُ أَنَّ اللَّهَ قَدْ شَرَحَ صَدْرَ أَبِي بَكْرٍ لِلْقِتَالِ فَعَرَفْتُ أَنَّهُ الْحَقُّ