Praise be to Allah.
Reciting al-Faatihah at the time of the marriage contract or engagement has nothing to do with the Sunnah; rather it is an innovation (bid‘ah). It is not permissible to single out any part of the Qur’an for any actions except on the basis of evidence.
Abu Shaamah al-Maqdisi said in al-Baa‘ith ‘ala Inkaar al-Bida‘ wa’l-Hawaadith (165):
It is not appropriate to single out times for acts of worship that were not singled out for such acts in Islamic teachings. People have no authority decide such matters; rather that is the prerogative of the Lawgiver. End quote.
The scholars of the Standing Committee for Issuing Fatwas were asked:
Is reciting al-Faatihah at the time when a man gets engaged to a woman an innovation (bid ‘ah)?
Reciting al-Faatihah at the time of a man's proposal to a woman or at the time of his marriage contract with her is an innovation. End quote.
None of the rulings of the marriage contract come into effect as a consequence of reciting al-Faatihah. Reciting al-Faatihah does not mean that the marriage contract has been completed; rather what matters is the proposal and acceptance with the wali (woman’s guardian) and witnesses.
The Sunnah is to recite khutbat al-haajah at the time of the marriage contract.
It was narrated that ‘Abdullah ibn Mas‘ood (may Allaah be pleased with him) said:
The Messenger of Allah (peace and blessings of Allah be upon him) taught us Khutbat al-Haajah, (to be said) at weddings and on other occasions:
“Inna al-hamda Lillaahi nasta’eenahu wa nastaghfiruhu, wa na’oodhu bihi min shuroori anfusinaa. Man yahdih Illaahu falaa mudilla lahu wa man yudlil falaa haadiya lahu. Wa ashhadu an laa ilaaha ill-Allaah wa ashhadu anna Muhammadan ‘abduhu wa rasooluhu (Verily, all praise is to Allah, we seek His help and His forgiveness. We seek refuge with Him from the evil of our own souls. Whomsoever Allah guides will never be led astray, and whomsoever Allah leaves astray, no one can guide. I bear witness that there is no god but Allah, and I bear witness that Muhammad is His slave and Messenger).
‘Yaa ayyuha’n-naas uttaqu rabbakum alladhi khalaqakum min nafsin waahidatin wa khalaqa minhaa zawjahaa wa baththa minhumaa rijaalan katheeran wa nisaa’an wa’ttaqu-Llaah alladhi tasaa’aloona bihi wa’l-arhaama inna Allaaha kaana ‘alaykum raqeeban (O mankind! Be dutiful to your Lord, Who created you from a single person, and from him He created his wife, and from them both He created many men and women, and fear Allah through Whom you demand your mutual (rights), and (do not cut the relations of) the wombs (kinship) Surely, Allah is Ever an All-Watcher over you).’ [al-Nisaa’ 4:1]
‘Yaa ayyuha’lladheena aamanu-ttaqu’Llaaha haqqa tuqaatihi wa laa tamootunna illaa wa antum muslimoon (O you who believe! Fear Allah as He should be feared, and die not except in a state of Islam (as Muslims) with complete submission to Allah.)’ [Aal ‘Imraan 3:102]
‘Yaa ayyahu’lladheena aamanu-ttaqu’Llaaha wa qooloo qawlan sadeedan yuslih lakum a’maalakum wa yaghfir lakum dhunoobakum wa man yuti’ Allaaha wa rasoolahu fa qad faaza fawzan ‘azeeman (O you who believe! Keep your duty to Allah and fear Him, and speak (always) the truth). He will direct you to do righteous good deeds and will forgive you your sins. And whosoever obeys Allah and His Messenger, he has indeed achieved a great achievement (i.e. he will be saved from the Hell‑fire and will be admitted to Paradise)’ [al-Ahzaab 33:70, 71].”
Narrated by Abu Dawood (2118) and classed as saheeh by al-Albaani in Saheeh Abi Dawood.
The people have turned away from this Sunnah and adhered to this bid ‘ah. We ask Allah, may He be exalted, to bring the Muslims back to their religion in the best way.
And Allah knows best.