We wanted to perform congregational prayer together with our family members, however, there is only one boy while the rest are women. The question is, is it permissible to pray in congregation behind the child?
Alhamdulillah, praise and thanks to Allah for the countless blessings He has blessed us all with. Blessings and salutations to the Prophet Muhammad PBUH, his wives, his family, companions and all those that follow his teachings to the day of judgement.
For the introduction, we start with a hadith which tells the story of Amru bin Salamah who became an imam of his tribe during the time of the Prophet PBUH while he was six or seven years old. This is in accordance with a hadith narrated by Amru bin Salamah R.Anhu:
قَالَ " صَلُّوا صَلاَةَ كَذَا فِي حِينِ كَذَا، وَصَلُّوا كَذَا فِي حِينِ كَذَا، فَإِذَا حَضَرَتِ الصَّلاَةُ، فَلْيُؤَذِّنْ أَحَدُكُمْ، وَلْيَؤُمَّكُمْ أَكْثَرُكُمْ قُرْآنًا ". فَنَظَرُوا فَلَمْ يَكُنْ أَحَدٌ أَكْثَرَ قُرْآنًا مِنِّي، لِمَا كُنْتُ أَتَلَقَّى مِنَ الرُّكْبَانِ، فَقَدَّمُونِي بَيْنَ أَيْدِيهِمْ، وَأَنَا ابْنُ سِتٍّ أَوْ سَبْعِ، سِنِينَ وَكَانَتْ عَلَىَّ بُرْدَةٌ، كُنْتُ إِذَا سَجَدْتُ تَقَلَّصَتْ عَنِّي، فَقَالَتِ امْرَأَةٌ مِنَ الْحَىِّ أَلاَ تُغَطُّوا عَنَّا اسْتَ قَارِئِكُمْ. فَاشْتَرَوْا فَقَطَعُوا لِي قَمِيصًا، فَمَا فَرِحْتُ بِشَىْءٍ فَرَحِي بِذَلِكَ الْقَمِيصِ
The Prophet (ﷺ) afterwards said to them, 'Offer such-and-such prayer at such-and-such time, and when the time for the prayer becomes due, then one of you should pronounce the Adhan (for the prayer), and let the one amongst you who knows Qur'an most should, lead the prayer." So they looked for such a person and found none who knew more Qur'an than I because of the Qur'anic material which I used to learn from the caravans. They therefore made me their Imam ((to lead the prayer) and at that time I was a boy of six or seven years, wearing a Burda (i.e. a black square garment) proved to be very short for me (and my body became partly naked). A lady from the tribe said, "Won't you cover the anus of your reciter for us?" So they bought (a piece of cloth) and made a shirt for me. I had never been so happy with anything before as I was with that shirt.
Sahih al-Bukhari (4302)
This hadith is evidence used by jurists of madhhab al-Shafi’e (Shafi’e scholars) that it is valid for a mumayyiz child to be an imam in obligatory prayers. (See Fath al-Bari 8/ 23)
Imam al-Nawawi Rahimahullah said in Majmu’:
قَالَ الْمُصَنِّفُ رَحِمَهُ اللَّه إذَا بَلَغَ الصَّبِيُّ حَدًّا يَعْقِلُ وَهُوَ مِنْ أهل الصلاة صحت امامته. وَقَوْلُ الْمُصَنِّفِ إذَا بَلَغَ حَدًّا يَعْقِلُ أَحْسَنُ مِنْ قَوْلِ مَنْ يَقُولُ إذَا بَلَغَ سَبْعَ سِنِينَ لِأَنَّ الْمُرَادَ أَنَّهُ إذَا كَانَ مُمَيِّزًا صَحَّتْ صَلَاتُهُ وَإِمَامَتُهُ وَالتَّمْيِيزُ يَخْتَلِفُ وَقْتُهُ بِاخْتِلَافِ الصِّبْيَانِ فَمِنْهُمْ مَنْ يَحْصُلُ لَهُ مِنْ سَبْعِ سِنِينَ وَمِنْهُمْ مَنْ يَحْصُلُ لَهُ قَبْلَهَا
When a child has grown up, he is eligible to be among people in prayer. So, his prayer is valid and it is also valid if he is an imam. Mumayyiz children whose prayer is considered valid is when he reaches the ability to reason well on what is good for him and when he already reaches seven years old. While the time of tamyiz (ability to differentiate between good and bad) is not the same for each child whether when he reaches seven years old or even before. (See al-Majmu’ Syarh al-Muhadzab 4/284)
Al-Khatib al-Sharbini said in his book:
وَ تَصِحُّ الْقُدْوَةُ (لِلْكَامِلِ) وَهُوَ الْبَالِغُ الْحُرُّ (بِالصَّبِيِّ) الْمُمَيِّزِ لِلِاعْتِدَادِ بِصَلَاتِهِ، «وَلِأَنَّ عَمْرَو بْنَ سَلِمَةَ بِكَسْرِ اللَّامِ كَانَ يَؤُمُّ قَوْمَهُ عَلَى عَهْدِ رَسُولِ اللَّهِ - صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ - وَهُوَ ابْنُ سِتٍّ أَوْ سَبْعٍ» ، رَوَاهُ الْبُخَارِيُّ.
وَلَكِنَّ الْبَالِغَ أَوْلَى مِنْ الصَّبِيِّ وَإِنْ كَانَ الصَّبِيُّ أَقْرَأَ أَوْ أَفْقَهَ لِلْإِجْمَاعِ عَلَى صِحَّةِ الِاقْتِدَاءِ بِهِ بِخِلَافِ الصَّبِيِّ، وَقَدْ نَصَّ فِي الْبُوَيْطِيِّ عَلَى كَرَاهَةِ الِاقْتِدَاءِ بِالصَّبِيِّ .وَتُكْرَهُ إمَامَةُ الْأَقْلَفِ بَعْدَ بُلُوغِهِ لَا قَبْلَهُ كَمَا قَالَهُ ابْنُ الصَّبَّاغِ
It is valid for a complete adult man who reached puberty and a free man to be a ma’mum to this child imam who is already mumayyiz. This is because the prayer of a child is valid according to the hadith of Amru bin Salamah R.Anhu who became an imam to his tribe during the time of the Prophet PBUH while being six or seven years old. However, a man who has reached puberty is prioritized (awla) than children even if they (the children) are more faqih and better in the recitation of al-Quran. This is in accordance with ijma’ ulama’ on the validity of praying behind an adult man, differ from behind a child. While it is cited in the book of al-Buwaiti that it is makruh to pray behind a child and it is also makruh to pray behind a quluf man (who is not circumcised yet) if he already reaches puberty (an adult) as mentioned by Ibn Sibagh (See Mughni al-Muhtaj 1/483). This means that an adult is prioritized than a child. Still, praying behind a mumayyiz child is valid.
While Imam al-Sayyid al-Bakri stated in his book:
اى وكره أيضا اقتداء بأقلف وهو الذى لم يختن ، سواء ما قَبْل البلوغ وما بعده ، لأنه قد لا يحافظ على ما يشترط لصحة صلاته ، فضلا عن إمامته ، وهو غسل جميع ما يصل إليه البول مماتحت قلفته لأنها لما كانت واجبة الإزالة كان ما تحتها فى حكم الظاهر
It is makruh to pray behind a quluf man (not yet circumcised) whether he has reached puberty or not. This is because, they may not observe one of the valid conditions of prayer, even more so when one of the valid conditions to be an imam is his body being pure by cleaning the part where urine may store (the skin part which is wajib to be circumcised) because when that part is obligated to be cut, so all parts under it are under the ruling of which is apparent. (See I’anah al-Thalibin 2/47).
However, al-Subki and his followers are of the opinion that it is not makruh to pray behind a quluf man if there is no other congregation, in fact, it is prioritized to pray behind him than praying alone. (See I’anah al-Thalibin 2/48). This can be understood that the prayer of a man who has yet to be circumcised is closely related to the cleanliness of the part where urine comes in contact with. So, it is valid for uncircumcised man to pray after purifying the part in order to observe one of the valid conditions of praying.
A piece of additional information, a woman cannot be an imam to a man. Kindly refer to Bayan Linnas Series 91: Man Praying Behind a Woman  and Al-Kafi #888: Who is More Rightful to Be the Imam? 
After analyzing the arguments from the jurists above, we conclude the following points:
- It is afdhal (prioritized) to choose imam from among the adult following the order of eligibility than an imam from among the mummayiz children.
- However, if there is no choice, mumayyiz children may become the imam for both obligatory and Sunnah prayers.
- For children who are uncircumcised (quluf), their prayers are valid after they purify the part which urine may store which is one of the valid conditions of praying. However, it is better to choose imam who is circumcised.
- Children who are chosen to be the imam should be able to recite al-Quran and know the valid conditions of prayer and being an imam.
- The question asked is related to the situation where there is no single adult man to be an imam and the rest of the family members are women. So, it is permissible for the children to be the imam in that situation if he is able to recite al-Quran properly and already reach the level of mumayyiz (able to differentiate between good and bad) which is seven years old or before it.
Lastly, may the explanation give us the correct understanding in religion.