We came in to see him, and he asked his wife, "When should a child begin to pray?"She replied, "A man among us used to relate from the Messenger of Allah ﷺ that he was asked about this, and he said, 'When he can tell his right hand from his left, then instruct him to pray.'"
حدثنا سليمان بن داود المهري حدثنا ابن وهب حدثنا هشام بن سعد
دخلنا عليه فقال لامرأته متى يصلي الصبي فقالت كان رجل منا يذكر عن رسول الله ﷺ أنه سئل عن ذلك فقال إذا عرف يمينه من شماله فمروه بالصلاة
No references are available.
Sourcing, its isnad is daif. Bayhaqi narrated it, 3/84, from the hadith of Abdullah bin Wahb through this route, and its chain is daif, the woman is unknown and I could not identify the man. The hadith has an irregular route recorded by Tabarani in al-Saghir, 1/99.