Ikrimah said: A group of people from Iraq said: Ibn Abbas, what is your opinion about the verse in which we have been commanded whatever we have been commanded, but no one acts upon it? The word of Allah, Most High, reads: "O ye who believe! Let those whom your right hands possess, and the (children) among you, who have not come of age, ask your permission (before) they enter your presence on three occasions: before morning prayer, while you are undressing for the noonday heat, and after late-night prayer. These are your three times of undress; outside those times it is not wrong for you or for them to move about." Al-Qa'nabi recited the verse up to "full of knowledge and wisdom". Ibn Abbas said: Allah is Most Clement and Most Merciful to the believers. He loves concealment. The people had neither curtains nor curtained canopies in their houses. Sometimes a servant, a child or a female orphan of a man entered while the man was having sexual intercourse with his wife. So Allah commanded them to ask permission in those times of undress. Then Allah brought them curtains and all good things. But I did not see anyone following it after that. Abu Dawud said: The tradition of 'Ubaid Allah and of 'Ata, weakens this tradition.

The Messenger of Allah (ﷺ) said: Command your children to pray when they become seven years old, and beat them for it (prayer) when they become ten years old; and arrange their beds (to sleep) separately.

“Umar used to ask me questions in front of the Companions of the Prophet. So Abdur-Rahman bin Awf said to him: ‘Why do you ask him, while we have children like him?’” He said: “Umar said to him: ‘It is because of what you know (about him).’ So he asked him about this Ayah: ‘When there comes the help of Allah and the Conquest.’ I said: “It is only regarding the (end of the) life span of the Messenger of Allah, informing him of it.” Then he recited the Surat until its end. So Umar said to him: “By Allah! I know not about it, but what you know.”

Hisham ibn Sa'd reported: We entered upon Mu'adh ibn Abdullah ibn Khubayb al-Juhani. He said to his wife: When (at what age) should a boy pray? She replied: Some person of us reported: The Messenger of Allah (ﷺ) was asked about it; he said: When a boy distinguishes right hand from the left hand, then command him to pray.

as above (the sub narrators are different). Abu Huraira qualified the three children referred to in the above mentioned Hadith as not having reached the age of committing sins (i.e. age of puberty) .