All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
The Imam in congregational prayer is the leader of the people to Allah the Almighty, leading them in the greatest of the rituals of Islam, which is prayer. Therefore, his position has a high status in our religion. The first to take it was our Prophet (PBUH), and then the Imams followed him. For the sake of achieving success in this great task, the Prophet (PBUH) prayed for the Imams, so that Allah the Almighty would grant them success in upholding the rights of the Imama (Leadership of prayer).
Abu Hurairah (May Allah be pleased with him) said: The Messenger of Allah (PBUH) said: "The Imam is a guarantor, and the Muezzin is a trustee. O Allah, guide the Imams and forgive the Muezzins." (Transmitted by Abu Dawoud). His saying (PBUH): "The Imam is a guarantor" includes many meanings of guarantee that the scholars have agreed upon in the chapters of congregational prayer.
The one who should be given the Imama first is the most knowledgeable in the rulings of prayer, then the one who is most proficient in reciting the Quran, then the one who is the oldest. The Messenger of Allah (PBUH) said: "The person who is best versed in the recitation of the Book of Allah, should lead the prayer. However, if all those present are equally versed in it, then the one who has most knowledge of the Sunnah; if they are equal in that respect too, then the one who has emigrated (to Al-Madinah) first, if they are equal in this respect also, then the oldest of them. No man should lead another in prayer where the latter has authority, or sit in his house, without his permission." {Transmitted by Muslim}.
"It is Sunnah (practice of the Prophet) that the people be led in prayer by the one who is most proficient in reciting the Quran and most knowledgeable in fiqh (Islamic jurisprudence). This is based on the Hadith narrated by Abu Mas'ud al-Badri, who said that the Prophet (PBUH) said: "The one who should lead the people in prayer is the one who is most proficient in reciting the Quran and the most frequent reciter. If their recitation is equal, then the one who has migrated earlier should lead them. If they are equal in migration, then the one who is older should lead them." The majority of the Companions (May Allah be pleased with them) were more proficient in reciting the Quran than they were in fiqh, because they would recite the ayah (Verse of Quran) and learn its rulings. In addition, since the validity of prayer depends on recitation and fiqh, the people who are most proficient in these two matters should be given priority. If one of them is superior in recitation or fiqh, then he should lead. If one of them is superior in fiqh and the other is superior in recitation, then the one who is more knowledgeable in fiqh should lead, because there may be an incident in prayer that requires Ijtihad (Independent legal reasoning). If they are equal in fiqh and recitation, then there are two opinions. The old opinion is that the one who is more noble should lead, then the one who has migrated earlier, then the one who is older. This is the most correct opinion." {Al-Majmou` Shareh Al-Mohazab, V.4:279 by An-Nawawi}.
"It is preferable that the prayer leader be an adult who is proficient in reciting the Quran and knowledgeable in the rulings of prayer according to the previous sequence, even if his voice is not beautiful. The Imama of a young boy who has reached the age of seven and is proficient in reciting the Quran and has knowledge of the rulings of prayer is valid if there is no adult who meets the conditions for valid Imama. However, scholars have stated that this is Makruh (disliked)."
Al-Khatib Al-Sharbini, the Shafi'i scholar, said: "It is valid for an adult male to be led in prayer by a young boy who has reached the age of discernment because his leading the prayer is considered valid. This is also because `Amr ibn Salimah used to lead his people in prayer during the time of the Prophet (PBUH) when he (`Amr) was six or seven years old." (Transmitted by Al-Bukhari).
"However, an adult is preferable to a boy, even if the boy is more proficient in reciting the Quran or more knowledgeable in fiqh. This is because there is a consensus on the validity of following an adult, unlike following a boy. It has been stated in Al-Buwaiti that it is Makruh (disliked) to follow a boy as an Imam." {Moghni Al-Muhtaj, V.1:483}.
Therefore, an adult who is knowledgeable about the rulings of prayer is more deserving to be given the Imama (Leadership of prayer). It is not appropriate to give the Imama to young boys if there is an adult who is proficient. However, if this is done, then their prayer is valid, although it is disliked. Moreover, it is important to ensure that giving the Imama to a young boy does not cause discord or conflict among the worshippers in the mosque. And Allah the Almighty knows best.
