The word(s) "expiation" appears 5 time(s) in 4 verse(s) in Quran in Mohsin Khan translation.

(1) And make not Allah's (Name) an excuse in your oaths against your doing good and acting piously, and making peace among mankind. And Allah is All-Hearer, All-Knower (i.e. do not swear much and if you have sworn against doing something good then give an expiation for the oath and do good).

(2) And We ordained therein for them: "Life for life, eye for eye, nose for nose, ear for ear, tooth for tooth, and wounds equal for equal." But if anyone remits the retaliation by way of charity, it shall be for him an expiation. And whosoever does not judge by that which Allah has revealed, such are the Zalimun (polytheists and wrong-doers - of a lesser degree).

(3) Allah 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 Masakin (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 . And protect your oaths (i.e. do not swear much) . Thus Allah make clear to you His Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) that you may be grateful.

(4) O you who believe! Kill not the game while you are in a state of Ihram [for Hajj or 'Umrah (pilgrimage)], and whosoever of you kills it intentionally, the penalty is an offering, brought to the Ka'bah, of an eatable animal (i.e. sheep, goat, cow) equivalent to the one he killed, as adjudged by two just men among you; or, for expiation, he should feed Masakin (poor persons), or its equivalent in Saum (fasting), that he may taste the heaviness (punishment) of his deed. Allah has forgiven what is past, but whosoever commits it again, Allah will take retribution from him. And Allah is All-Mighty, All-Able of Retribution.