While we were walking with the Messenger of Allah ﷺ, he passed by some boys who were playing, and among them was Ibn Sayyad. The Messenger of Allah ﷺ said, "May your hands be covered in dust, do you bear witness that I am the Messenger of Allah?"He replied, "Do you bear witness that I am the messenger of Allah?"Umar, may Allah be pleased with him, said, "Let me strike his neck."The Messenger of Allah ﷺ said, "If he is the one you fear, you will never be able to overcome him."
حدثنا يونس حدثنا المعتمر عن أبيه عن سليمان الأعمش عن شقيق بن سلمة
بينما نحن مع رسول الله ﷺ نمشي إذ مر بصبيان يلعبون فيهم ابن صياد فقال رسول الله ﷺ تربت يداك أتشهد أني رسول الله فقال هو أتشهد أني رسول الله قال فقال عمر رضي الله تعالى عنه دعني فلأضرب عنقه قال فقال رسول الله ﷺ إن يك الذي تخاف فلن تستطيعه
Its isnad is sahih. Muslim narrated it, 2:372, through the route of Jareer from Amash, and something similar in meaning has already passed at 3610.