It is narrated from Sayyiduna Ibn Amr, may Allah be pleased with him, that the Noble Prophet, peace and blessings be upon him, said: "When children reach the age of seven, command them to pray; and when they reach the age of ten, punish them for abandoning prayer, and separate their sleeping beds."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 6689