The basest creatures in the sight of Allah are the faithless who will not believe; those who time after time violate their treaties with you and have no fear of Allah. If you capture them in battle discriminate between them and those that follow them, so that their followers may take warning.
If you fear treachery from any of your allies, you may fairly retaliate by breaking off your treaty with them. Allah does not love the treacherous.
Proclaim a woeful punishment to the unbelievers, except to those idolaters who have honored their treaties with you in every detail and aided none against you. With these keep faith, until their treaties have run their term. Allah loves the righteous.
When the sacred months are over slay the idolaters wherever you find them. Arrest them, besiege them, and lie in ambush everywhere for them. If they repent and take to prayer, and render the alms levy, allow them to go their way. Allah is forgiving and merciful.
If after coming to terms with you, they break their oaths, and revile your faith, make war on the leaders of unbelief – for no oaths are binding with them – so that they may desist
Will you not fight against those who have broken their oaths and conspired to banish the apostle? They were the first to attack you. Do you fear them? Surely Allah is more deserving of your fear, if you are true believers.
Make war on them. Allah will chastise them at your hands and humble them. He will grant you victory over them and heal the spirit of the faithful. He will take away all rancor from their hearts: Allah shows mercy to whom He pleases. Allah is all-knowing and wise.
Make no covenant with the people of the land
12 Take heed to yourself, lest you make a covenant with the inhabitants of the land where you are going, lest it be a snare in your midst. 13 But you shall destroy their altars, break their sacred pillars, and cut down their wooden images 14(for you shall worship no other god, for the LORD, whose name is Jealous, is a jealous God), 15 lest you make a covenant with the inhabitants of the land, and they play the harlot with their gods and make sacrifice to their gods, and one of them invites you and you eat of his sacrifice, 16 and you take of his daughters for your sons, and his daughters play the harlot with their gods and make your sons play the harlot with their gods. 17 You shall make no molded gods for yourselves.
Exodus 34:12-17 NKJV
If a man vows a vow to the LORD, or swears an oath to bind himself by some agreement, he shall not break his word; he shall do according to all that proceeds out of his mouth.