Oaths and Promises
[5:89] Allah does not call you to account for what is vain in your oaths, but He calls you to account for the making of deliberate oaths; so its expiation is the feeding of ten poor men out of the middling (food) you feed your families with, or their clothing, or the freeing of a neck; but whosoever cannot find (means) then fasting for three days; this is the expiation of your oaths when you swear; and guard your oaths. Thus does Allah make clear to you His communications, that you may be Fateful.
[16:91] And fulfill the covenant of Allah when you have made a covenant, and do not break the oaths after making them fast, and you have indeed made Allah a surety for you; surely Allah knows what you do.
[16:92] And be not like her who unravels her yarn, disintegrating it into pieces after she has spun it strongly. You make your oaths to be means of deceit between you because (one) nation is more numerous than (another) nation. Allah only tries you by this; and He will most certainly make clear to you on the resurrection day that about which you differed.
[16:94] And do not make your oaths a means of deceit between you, lest a foot should slip after its stability and you should taste evil because you turned away from Allah's way and grievous punishment be your (lot).
[16:95] And do not take a small price in exchange for Allah's covenant; surely what is with Allah is better for you, did you but know.