Āmīn (Arabic: آمین) or amen literally means "may it be so" or "it is so". Among Muslims the word amin is commonly used with the same pronunciation meaning "respond to me", and the phrase "Ilahi amin" (Arabic: الهی آمین; meaning: O my God! respond to me) is very common among people today. It is used in English as amen (meaning: so be it).
In Hebrew, the word amin was first used as an adjective meaning "correct" and "true", but in the Book of Isaiah it was used as a noun. The word then turned into an invariant operator in Hebrew (meaning, "truly" and "of course"). It is used in this form 30 times in the Bible and 33 times in a Greek translation of the third century BC.
The occurrence of the word in the first book of Histories and the first book of Kings Books  may show that the word was used even before the fourth century BC in Jewish supplications and rituals. In the ancient Jewish tradition, the word was used at the beginning or the end of supplications. Its reiteration at the end of supplications, prayers and psalms was both a confirmation and endorsement of the relevant contents, and an expression of the hope that everyone could share the blessings of the practice in virtue of mentioning amen. In the period of Talmud and other Jewish traditions, it was important how to use the word in different conditions, and it was believed that God says "amen" to any supplication that is addressed to Him.
The Jewish tradition found its way into Christian churches. The word "Amin" was used in the New Testament 119 times, 52 cases of which are used differently from how it is used in Judaism. Through the New Testament, the word entered almost all main languages in the world.
The word, amin, as used in the New Testament, has four meanings:
- Acknowledgement and endorsement; agreement or participation in a supplication, and an expression of one's pledge.
- Request of divine response, meaning: "O God! Accept or respond!"
- Confirmation of a supplication or a pledge, meaning: "So be it" (today the word is used at the end of supplications to imply the latter two meanings).
- An attribute or a name of Jesus the Christ (a).
Since both Judaism and Nazarene Christianity had followers in the Arabian Peninsula before the emergence of Islam, it is probable that Arabs, including those in Mecca and Medina, were familiar with it, although no trace of it is found in poems of the Jahiliyya period. The word does not occur in the Qur'an, but early Muslims were definitely familiar with the word. The Prophet Muhammad (s) used the word, but it seems that early Muslims were not sure about the meaning of the word, since the Prophet (s) gave them an explanation and an interpretation of the word (by saying that "amin is a divine stamp on His faithful servants"). And 'Abd Allah b. al-'Abbas tried to give a grammatical account of the word.
In Exegeses of the Holy Qur'an
The word is mentioned in exegeses of the Qur'an 10:88 and 89. According to almost all exegetes of the Qur'an, when the Prophet Moses (a) cursed the Pharaoh, he and his brother, the prophet Aaron (a), cited the word amen.
Citing Amin in the Prayer
Sunni Muslims cite the word, amin, after reciting Qur'an 1 in the prayer as a reply to the verse, "Show us the right path", (Quran, 1:6). If the worshiper says his or her prayer individually, then they cite the word on their own, and if they say a congregational prayer, when the leader of the prayer finishes reciting Qur'an 1, all followers cite amin together. Shiite jurists maintain that citing amin in the prayer invalidates it, since this is a heretic practice in the prayer that is not known to be confirmed in the tradition of the Prophet (s).
- Isaiah 65:16
- Blessed be the LORD, the God of Israel, from everlasting to everlasting." Then all the people said "Amen!". 1 Chronicles 16:36
- Benaiah son of Jehoiada answered the king, "Amen". King 1:36
- The material for this article is mainly taken from آمین in Farsi WikiShia.