What is the ruling on prayer for one who has not reached puberty?

Prayer is obligatory only for an adult of sound mind. It is not obligatory for someone who has not reached puberty. However, their guardian should command them to perform it when they reach seven years of age, and lightly strike them for abandoning it when they reach ten, because the Prophet, peace and blessings be upon him, said: "Command your children to pray when they are seven, and strike them for it when they are ten, and separate them in beds."