There was an Ijma (إجماع i.e. CONSENSUS) of Muslim Ummah that marriage with a minor girl is allowed. But in the present century, few modern Muslim Preachers (and Quranists, i.e. those who reject Hadith) have started denying it. They are trying to misuse verse 4:6 as an argument to deny marriage to minor girls in Islam. 

Verse 4:6:

وَٱبْتَلُوا۟ ٱلْيَتَٰمَىٰ حَتَّىٰٓ إِذَا بَلَغُوا۟ ٱلنِّكَاحَ فَإِنْ ءَانَسْتُم مِّنْهُمْ رُشْدًا فَٱدْفَعُوٓا۟ إِلَيْهِمْ أَمْوَٰلَهُمْ

And test the orphans until when they reached the age of marriage (Nikah), then if you perceive in them sound judgement then deliver to them their wealth.

Modern Muslim preachers claim that one gets sound judgement about one's wealth when one is already an adult person. Thus, this means that Islam prescribed that one can marry only after becoming an adult. 

Response:

The largest Muslim Fatwa website Islam Q&A writes:

أن الآية الكريمة ليس فيها منع تزويج الصغير أو الصغيرة، ولم تسق لبيان موضوع التزويج، وإنما هي في إيتاء المال لليتامى، وأن ذلك يكون بعد البلوغ،

The noble verse does not prohibit the marriage of minors, and it does not provide any clarification regarding the subject of marriage. Rather, it pertains to giving wealth to orphans, indicating that this should occur after they reach puberty. 

Please note that the word Nikah has a double meaning in the Arabic language:

  1. According to the Islamic Sharia, "Nikah" is a terminology, whose meaning in Islamic Sharia is “marriage”. 
  2. While the literal meaning of “Nikah” in the Arabic language is "To do Sexual Intercourse"

It becomes even more evident from another verse of Quran 17:34:

Quran 17:34

وَلَا تَقْرَبُوا۟ مَالَ ٱلْيَتِيمِ إِلَّا بِٱلَّتِى هِىَ أَحْسَنُ حَتَّىٰ يَبْلُغَ أَشُدَّهُۥ ۚ
Come not nigh to the orphan's property except to improve it, until he attains the age of full strength

The word أَشُدَّهُ (full strength) in this verse means the age when young boys and girls start feeling the desire/strength to have sexual intercourse.

Please note that:

  • As far as Shar'i Nikah (marriage) is concerned, then there is no condition present in it of reaching the أَشُدَّهُ (i.e. Full Strength to do the act of intercourse).
  • The proof is that prophet Muhammad himself did the Shar'i Nikah with 'Aisha when she was only 6 years old.
  • And no one tests a 6-year-old child for handing over his/her property to him/her, as a 6-year-old child has neither أَشُدَّهُ (Strength/Desire) nor he/she has any kind of “sound judgement” to look after his/her property.

Thus, the Shar'i Nikah has nothing to do with the أَشُدَّهُ (strength), as Muhammad did this Shar'i Nikah with 6 years 'Aisha.

Actually, even at the age of 9, when 'Aisha finally came to the house of Muhammad for the consummation of marriage, she was still not mentally sound enough to look after any property or business. It is evident from the following hadith:

Sahih Bukhari 6130:

Narrated `Aisha: I used to play with the dolls in the presence of the Prophet, and my girl friends also used to play with me. When Allah's Messenger (ﷺ) used to enter (my dwelling place) they used to hide themselves, but the Prophet would call them to join and play with me.

Fourthly, according to Islamic Sharia:

  • When a girl reaches puberty, then she herself gets the right to give her consent for the marriage or to deny the marriage.
  • But if she is a minor or prepubescent girl, then her father/guardian could wed her to anyone, even without her consent (link).
  • And if she is prepubescent and also an orphan, then her guardian has the right to wed her with himself (even without her consent), in order to get her property and wealth.

It is evident from the following Hadith:

Sahih Bukhari 5064:

Narrated 'Urwa: that he asked `Aisha about the Statement of Allah: 'If you fear that you shall not be able to deal justly with the orphan girls, then marry (other) women of your choice, two or three or four; but if you fear that you shall not be able to deal justly (with them), then only one, or (the captives) that your right hands possess. That will be nearer to prevent you from doing injustice.' (4.3) `Aisha said, "O my nephew! (This Verse has been revealed in connection with) an orphan girl under the guardianship of her guardian who is attracted by her wealth and beauty and intends to marry her with a Mahr (bride-dowry) less than what other women of her standard deserve. So they (such guardians) have been forbidden to marry them unless they do justice to them and give them their full Mahr, and they are ordered to marry other women instead of them."

It is also evident from the following Quranic Verse:

Quran 4:127:

You also read them (the guardians) in the Book concerning orphaned women (in your charge) to whom you deny their ordained rights and yet wish to take them in marriage, as well as in respect of helpless children, that you should be just in the matter of orphans." The good you do is known to God.

The orphan girl, in the above tradition, is a small orphan girl who has not yet reached puberty. It is due to the reasons that:

  • Firstly, after becoming an adult, the guardian cannot compel her to marry him without her consent. 
  • Secondly, after becoming an adult, the guardian cannot marry her by giving her less than a standard dowry (i.e. Haq Mehr). 
  • Thirdly, after becoming an adult, she will get full control of her money and property too, and thus the guardian cannot take control of her property any more. 
  • Fourthly, after becoming an adult, she is no longer considered an orphan. 

Moreover, Islamqa.com, one of the largest Fatwa sites on the internet, also refutes these modern Muslim preachers regarding verse 6:4 (link):

This verse 4:6 explains that an orphan’s money is given to him/her after they reach puberty and attain sound judgement. What’s meant by sound judgment is sound management of money. This can only happen after puberty.
“Reaching Nikah” mentioned in the verse means reaching puberty which can be known through sings such as menstruation for females and the growth of pubic hair. The verse used the expression “reaching Nikah” to actually mean “reaching puberty” because in most cases, it’s adults who perform Nikah. But this doesn’t mean that it’s not possible for non-adults to perform Nikah, which is permissible as proven by the Quran, Sunnah and the consensus of scholars. Plus, the same Surah and the same context of verses proves it (the permissibility of child marriage). (The verse that speaks about giving an orphan his money when he/she reaches Nikah is verse no.6) Verse no.3 says: “And if you fear that you shall not be able to deal justly with the orphangirls, then marry (other) women of your choice, two or three, or four but if you fear that you shall not be able to deal justly (with them), then only one or (the captives and the slaves) that your right hands possess. ”.
This verse proves it’s allowed to marry an orphan. And an orphan cannot be an adult. It’s reported in Sahih Bukhari Hadith no. 2494: “Narrated Urwah that he asked `Aisha regarding the Verse: 'If you fear that you shall not be able to deal justly with the orphan girls, marry (other) women of your choice.' (4.3) `Aisha said, "It is about an orphan girl under the custody of her guardian who being attracted by her wealth and beauty wants to marry her with Mahr less than other women of her status. So such guardians were forbidden to marry them unless they treat them justly by giving them their full Mahr. Then the people sought the verdict of Allah's Apostle for such cases, whereupon Allah revealed: 'They ask your instruction concerning women..' (4.127) “https://sunnah.com/bukhari:6965
Ibn Hajar (d.1449 AD) commented on this Hadith saying: “This shows it’s allowed to marry orphans who haven’t reached puberty. Because after puberty they can’t be called orphans.”

And Islamweb.Net (which is run by Qatari Ministry of Religious Affairs) writes (link):

“1. The two parties of the marriage contract (the wife and the husband) should be mature, free, and sound-minded. If one of them has a perplexed state of mind or is an indiscriminating minor, then the contract that he/she conducted is valid if her Wali agrees on that; otherwise, it is invalid.”

And Shia al-Islam.Org writes (link):

“Wilayah in Cases of Minority, Insanity and Idiocy: The legal schools concur that the guardian is authorized to contract marriage on behalf of his minor or insane ward (male or female).”

Muslim Preachers also claim that the Arabic word “Nisaa'” cannot refer to minor girls

Muslim preachers also come up with this excuse that the word Nisaa'  refers only to mature, adult women, therefore 65:4 cannot be talking about pre-pubescent females.[13] This linguistic argument does not hold water, even just on the basis of the Qur'an itself as a text. The word merely means “women/females” and can refer to mixed groups of women of various ages, as the English "female" or "women." Here are some verses that use the word "nisaa'":

Quran 2:49:

وَإِذْ نَجَّيْنَٰكُم مِّنْ ءَالِ فِرْعَوْنَ يَسُومُونَكُمْ سُوٓءَ ٱلْعَذَابِ يُذَبِّحُونَ أَبْنَآءَكُمْ وَيَسْتَحْيُونَ نِسَآءَكُمْ ۚ وَفِى ذَٰلِكُم بَلَآءٌ مِّن رَّبِّكُمْ عَظِيمٌ
And remember, We delivered you from the people of Pharaoh: They set you hard tasks and punishments, slaughtered your (newborn) sons and let your women-folk (i.e. newborn girls) live; therein was a tremendous trial from your Lord.

Quran 7:127:

وَقَالَ ٱلْمَلَأُ مِن قَوْمِ فِرْعَوْنَ أَتَذَرُ مُوسَىٰ وَقَوْمَهُۥ لِيُفْسِدُوا۟ فِى ٱلْأَرْضِ وَيَذَرَكَ وَءَالِهَتَكَ ۚ قَالَ سَنُقَتِّلُ أَبْنَآءَهُمْ وَنَسْتَحْىِۦ نِسَآءَهُمْ وَإِنَّا فَوْقَهُمْ قَٰهِرُونَ
Said the chiefs of Pharaoh’s people: “Wilt thou leave Moses and his people, to spread mischief in the land, and to abandon thee and thy gods?” He said: “Their (newborn) male children will we slay; (only) their (newborn) females will we save alive; and we have over them (power) irresistible."

In the above verses, the word "Nisaa'" is referring to female infants.

Moreover, the Quran used the expression “Nisaa’ orphans” to mean “female orphans”. Orphans cannot be adults which means non-adults can be included in the word Nisaa’.

Quran 4:127:

‏ويستفتونك في النساء قل الله يفتيكم فيهن ومايتلى عليكم في الكتاب في يتامى النساء اللاتي لاتؤتونهن ماكتب لهن وترغبون ان تنكحوهن والمستضعفين من الولدان وان تقوموا لليتامى بالقسط وماتفعلوا من خير فان الله كان به عليماThey consult thee concerning women. Say: Allah giveth you decree concerning them, and the Scripture which hath been recited unto you (giveth decree), concerning female orphans and those unto whom ye give not that which is ordained for them though ye desire to marry them, and (concerning) the weak among children, and that ye should deal justly with orphans. Whatever good ye do, lo! Allah is ever Aware of it.