Allah said,

[وَالَّذِينَ ءَامَنُواْ وَلَمْ يُهَاجِرُواْ مَا لَكُم مِّن وَلـيَتِهِم مِّن شَىْءٍ حَتَّى يُهَاجِرُواْ]

(And as to those who believed but did not emigrate, you owe no duty of protection to them until they emigrate,) [8:72].

This is the third category of believers, those who believed, but did not perform Hijrah and instead remained in their areas. They do not have any share in the war booty or in the fifth [designated for Allah and His Messenger, the relatives of the Prophet , the orphans, the poor and the wayfarer], unless they attend battle.

Imam Ahmad recorded that Buraydah bin Al-Hasib Al-Aslami said, "When the Messenger of Allah would send a commander with an expedition force or an army, he would advise him to have Taqwa of Allah and be kind to the Muslims under his command. He used to say,

«اغْزُوا بِاسْمِ اللهِ فِي سَبِيلِ اللهِ، قَاتِلُوا مَنْ كَفَرَ بِاللهِ، إِذَا لَقِيتَ عَدُوَّكَ مِنَ الْمُشْرِكِينَ فَادْعُهُمْ إِلَى إِحْدَى ثَلَاثِ خِصَالٍ أَوْ خِلَالٍ فَأَيَّتُهُنَّ مَا أَجَابُوكَ إِلَيْهَا فَاقْبَلْ مِنْهُمْ، وَكُفَّ عَنْهُمْ. ادْعُهُمْ إِلَى الْإِسْلَامِ، فَإِنْ أَجَابُوكَ فَاقْبَلْ مِنْهُمْ وَكُفَّ عَنْهُمْ. ثُمَّ ادْعُهُمْ إِلَى التَّحَوُّلِ مِنْ دَارِهِمْ إِلَى دَارِ الْمُهَاجِرِينَ، وَأَعْلِمْهُمْ إِنْ فَعَلُوا ذَلِكَ أَنَّ لَهُمْ مَا لِلْمُهَاجِرِينَ، وَأَنَّ عَلَيْهِمْ مَا عَلَى الْمُهَاجِرِينَ، فَإِنْ أَبَوْا وَاخْتَارُوا دَارَهُمْ، فَأَعْلِمْهُمْ أَنَّهُمْ يَكُونُونَ كَأَعْرَابِ الْمُسْلِمِينَ، يَجْرِي عَلَيْهِمْ حُكْمُ اللهِ الَّذِي يَجْرِي عَلَى الْمُؤْمِنِينَ، وَلَا يَكُونُ لَهُمْ فِي الْفَيْءِ وَالْغَنِيمَةِ نَصِيبٌ،إِلَّا أَنْ يُجَاهِدُوا مَعَ الْمُسْلِمِينَ، فَإِنْ هُمْ أَبَوْا، فَادْعُهُمْ إِلَى إِعْطَاءِ الْجِزْيَةِ. فَإِنْ أَجَابُوا فَاقْبَلْ مِنْهُمْ وَكُفَّ عَنْهُمْ، فَإِنْ أَبَوْا فَاسْتَعِنْ بِاللهِ ثُمَّ قَاتِلْهُم»

(Fight in the Name of Allah, in the cause of Allah. Fight those who disbelieve in Allah. When you meet your Mushrik enemy, then call them to one of three choices, and whichever they agree to, then accept it and turn away from them. Call them to embrace Islam, and if they agree, accept it from them and turn away from them. Then call them to leave their area and come to areas in which the Muhajirin reside. Make known to them that if they do this, they will have the rights, as well as, the duties of the Muhajirin. If they refuse and decide to remain in their area, make known to them that they will be just like Muslim bedouins, and that Allah's law applies to them just as it does to all believers. However, they will not have a share in the war booty or Fai' (booty without war), unless they perform Jihad along with Muslims. If they refuse all of this, then call them to pay the Jizyah, and if they accept, then take it from them and turn away from them. If they refuse all these [three] options, then trust in Allah and fight them.)

Muslim collected this Hadith.

Allah said next,

[وَإِنِ اسْتَنصَرُوكُمْ فِى الدِّينِ فَعَلَيْكُمُ النَّصْرُ]

(But if they seek your help in religion, it is your duty to help them.)

Allah commands, if these bedouins, who did not perform Hijrah, ask you to aid them against their enemy, then aid them. It is incumbent on you to aid them in this case, because they are your brothers in Islam, unless they ask you to aid them against disbelievers with whom you have a fixed-term treaty of peace. In that case, do not betray your treaties or break your promises with those whom you have treaties of peace. This was reported from Ibn `Abbas.

[وَالَّذينَ كَفَرُواْ بَعْضُهُمْ أَوْلِيَآءُ بَعْضٍ إِلاَّ تَفْعَلُوهُ تَكُنْ فِتْنَةٌ فِى الاٌّرْضِ وَفَسَادٌ كَبِيرٌ ]

(73. And those who disbelieve are allies of one another, (and) if you (Muslims) do not do so (protect one another), there will be Fitnah on the earth, and great corruption.)