The Prophet ﷺ said: Command a boy to pray when he reaches the age of seven years. When he becomes ten years old, then beat him for prayer.
قَالَ النَّبِيُّ ﷺ مُرُوا الصَّبِيَّ بِالصَّلاَةِ إِذَا بَلَغَ سَبْعَ سِنِينَ وَإِذَا بَلَغَ عَشْرَ سِنِينَ فَاضْرِبُوهُ عَلَيْهَا