Jami` at-Tirmidhi 407
جامع الترمذي#407Sahih(Sabrah bin Ma'bad al-Juhni) narrated that:Allah's Messenger (S) said: "Teach the boy Salat when he is seven years old, and beat him (if he does not pray) when he is ten
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirHasan Sahih
Al-AlbaniHasan Sahih
Bashar Awad MaaroufHasan
Zubair Ali ZaiIsnaad Hasan
In-book reference: 2:260