Hawzah News Agency – The merciful prophet of Islam, peace be upon him and his household says:

الوَلدُ سَيّدٌ سبعَ سنينَ، وعبدٌ سبعَ سنينَ، ووزيرٌ سبعَ سنينَ، فإنْ رَضِيتَ أخلاقَهُ لإحدى‏ وعشرينَ، وإلّا فَاضْرِبْ على‏ جَنبِهِ، فقد أعْذَرتَ إلَى اللَّهِ تعالى‏.

'A child is a master for seven years, a slave for the next seven years, and a minister for another seven years. By the age of twenty one, you must either approve of his manners or cut him loose, for [by then] you would have fulfilled your obligation toward Allah, most High.'

Source: Makarim al-Akhlaq, v. 1, p. 478, no. 1649