Al-Maaida 5:89

Allah will not hold you accountable for your unintentional oaths[63], but He will hold you accountable for your deliberate oaths. The expiation thereof is to feed ten needy people from what you normally feed your own family, or to clothe them, or to emancipate a slave. However, if someone cannot afford it, then he must fast for three days. That is the expiation for breaking your oaths. But be mindful of your oaths[64]. This is how Allah makes His verses clear to you, so that you may be grateful.

[63] i.e., out of habit or without true intent.
[64] i.e., do not swear much; do not swear while lying; honor your oaths.

Allāh will not impose blame upon you for what is meaningless[279] in your oaths, but He will impose blame upon you for [breaking] what you intended of oaths. So its expiation[280] is the feeding of ten needy people from the average of that which you feed your [own] families or clothing them or the freeing of a slave. But whoever cannot find [or afford it] - then a fast of three days [is required]. That is the expiation for oaths when you have sworn. But guard your oaths.[281] Thus does Allāh make clear to you His verses [i.e., revealed law] that you may be grateful.

[279] i.e., what is sworn to only out of habit of speech or what one utters carelessly without true intent.
[280] i.e., that for a deliberate oath.
[281] i.e., do not take oaths indiscriminately or swear to do that which is sinful, requiring expiation.

89. Allâh will not punish you for what is unintentional in your oaths, but He will punish you for your deliberate oaths; for its expiation feed ten Masâkîn (poor persons), on a scale of the average of that with which you feed your own families, or clothe them or manumit a slave. But whosoever cannot afford (that), then he should fast for three days. That is the expiation for the oaths when you have sworn[28]. And protect your oaths (i.e. do not swear much)[29]. Thus Allâh make clear to you His Ayât (proofs, evidence, verses, lessons, signs, revelations, etc.) that you may be grateful.

[28] (V.5:89) Narrated Abu Hurairah رضي الله عنه: The Prophet صلى الله عليه وسلم said, "We (Muslims) are the last (to come) in the world, but (will be) foremost on the Day of Resurrection." Allâh’s Messenger صلى الله عليه وسلم also said, "By Allâh, if anyone of you insists on fulfilling an oath by which he may harm his family, he commits a greater sin in Allâh’s consideration than that of dissolving his oath and making its expiation with that which Allâh has commanded. (Sahih Al-Bukhâri, Vol.8, Hadîth No.621).
[29] (V.5:89) It is better not to take oaths, but if you have taken it, and later you find a better solution for the problem, then act according to the better one and give expiation for the oath.

Allah will not take you to task for that which is unintentional in your oaths, but He will take you to task for the oaths which ye swear in earnest. The expiation thereof is the feeding of ten of the needy with the average of that wherewith ye feed your own folk, or the clothing of them, or the liberation of a slave, and for him who findeth not (the wherewithal to do so) then a three days' fast. This is the expiation of your oaths when ye have sworn; and keep your oaths. Thus Allah expoundeth unto you His revelations in order that ye may give thanks.