Will you not fight a people who broke their oaths and planned to send out the messenger and they attacked you first? Do you fear them? Then Allah has more right that you should fear Him if you are believers. (Al Quran, Surah At-Taubah, Chapter 9: Verse 13)
The above verse shall be read in context with the following verses from Surah At-Taubah:
9-1: A declaration of immunity (Freedom from obligation) from Allah and His messenger to those of the polytheists with whom you made an agreement.
9-2: So move about (unrestricted) in the land for (another) four months, and know that you cannot frustrate Allah, and Allah will certainly disgrace the infidels.
9-3: And an announcement from Allah and His messenger to mankind on the day of the great pilgrimage that Allah and His messenger are free from obligation to the polytheists, so if you repent it will be better for you and if you turn back then know that you cannot frustrate Allah, and convey the news of a painful punishment to those who do not believe,
9-4: except those of the polytheists with whom you made an agreement then they did not go back in anything (of the agreement) nor did they help anyone against you, so fulfill for them their agreement till the completion of their term. Allah certainly loves those who guard (against evil).
9-5: Then when the sacred (prohibited) months pass off, then kill the polytheists wherever you find them and catch them and imprison them and sit for them at every place where you can watchfully wait (for them). But if they repent and establish worship (salat) and give charity (zakat) then leave their way free. Allah is certainly Protectively Forgiving, Merciful.
9-6: And if anyone of the polytheists seeks your protection then give him protection to the extent that he hears the word of Allah, then make him reach his (place of) safety. That is because they are a people who do not know. (R 1)
9-7: How can there be an agreement for the polytheists with Allah and with His messenger except those with whom you made an agreement near the Sacred Mosque? So as long as they are established (on the agreement) with regard to you, you (too) be established (on the agreement) with regard to them. Allah certainly loves those who guard (against evil).
9-8: How (can there be an agreement)? If they have an upper hand on you, they neither have regard for ties of relationship nor (their) responsibility of (fulfilling) a pact. They please you with their mouths but their hearts refuse and most of them are transgressors.
9-9: They have sold the signs of Allah for a small price, so they turn away (people) from His way, certainly their (deeds)! evil is that which they do.
9-10: In (the case of) a believer they neither have regard for ties of relationship nor (their) responsibility of a pact and those are the ones who exceed the limits.
9-11: So if they repent and establish worship (salat) and give charity (zakat) then they are your brothers in religion. Thus do We explain the signs in detail for a people who know.
9-12: And if they break their oaths after their agreement and taunt (you) in your religion then fight the leaders of infidelity that they may desist, because there is nothing (like a binding of) oaths for them.
9-13: Will you not fight a people who broke their oaths and planned to send out the messenger and they attacked you first? Do you fear them? Then Allah has more right that you should fear Him if you are believers.
9-14: Fight with them, Allah will punish them through your hands and disgrace them and help you against them and heal the bosoms (hearts) of the believing people,
9-15: and He will remove the anger of their hearts, and Allah turns (mercifully) to whom He wills and Allah is Knowing, Wise.
9-16: Did you suppose that you will be left alone, while Allah has not yet known (marked out) those of you who struggled (in His cause), and not taken any intimate friend besides Allah and His messenger and the believers? And Allah is informed of what you do (R 2)
9-17: It does not befit the polytheists that they should visit the mosques of Allah, being witnesses against themselves of (their) infidelity. Those are the persons whose deeds are fruitless and they will stay in the fire.
9-18: Only he shall visit the mosques of Allah who believes in Allah and the period hereafter and establishes worship (salat) and gives charity (zakat) and does not fear anyone except Allah, then it may be that such persons will be among those who are guided.
9-19: What! do you make (one who) gives drink to pilgrims and maintains the Sacred Mosque, like one who believes in Allah and the period hereafter and struggles in the way of Allah? With Allah, they are not equal. And Allah does not guide the unjust people.
9-20: Those who believed and migrated and struggled in the way of Allah with their wealth and their persons, they are greater in grade in the sight of Allah and those are the persons who achieve (the goal).
9-21: Their Fosterer conveys to them the good news of mercy from Him and (His) pleasure and gardens, wherein will be lasting happiness for them,
9-22: they will stay therein for ever. Certainly there is a great reward with Allah.
9-23: O you who believe! do not take your fathers and your brothers as your friends if they love infidelity instead of belief, and whoever of you takes them as a friend then those are the unjust persons.
9-24: Say, “If your fathers and your sons and your brothers and your mates and your family and friends and the wealth you have acquired and merchandise regarding which you fear that there will be no sale and the houses with which you are pleased, are dearer to you than Allah and His messenger and struggling in His way, then wait till Allah brings about His command and Allah does not guide the transgressing people.” (R 3)
Summarized Commentary:
During the Haj of 9 Hijri notice was given to the polytheists of Makkah with whom Prophet Muhammed (PBH) had made an agreement that within four months they should either accept Islam or be prepared for a war. There was an exception for those polytheists who had honoured the agreement, they were given time till the end of the term of the agreement. Muslims were also ordered to give protection to those polytheists who sought their protection and to make them hear the Quran so that they could accept Islam if they willed to and then to make
1. Blood relatives
2. Friends
3. Wealth
4. Business
5. Houses etc.
should not be preferred to
1. Allah (SWT),
2. His messenger (PBH) and
3. Struggling in His way i.e. these three should have top priority in life, which means that we should follow the message of Allah (SWT) [Quran], in accordance with the teachings of Prophet Muhammed (PBH) (Hadees) and struggle to propagate these among human beings mostly through our beliefs and practices.