‘Amr b. Shu'aib said on his father’s authority that his grandfather reported Allah's Messenger ﷺ as saying, “Command your children to observe prayer when they are seven years old, and beat them for [not observing] it when they are ten years old, and do not let [boys and girls] sleep together.” Abu Dawud transmitted it; and Baghawi transmitted it thus from him in Sharh as-sunna but in al-Masabih from Sabra b. Ma‘bad.