Usamah reported that the Messenger of Allah ﷺ would take hold of me and seat me on one of his thighs, and seat Hasan on his other thigh. Then he would embrace us both and say, "O Allah, have mercy on them, for I have mercy on them."
كان رسول الله ﷺ يأخذني فيقعدني على فخذه، ويقعد الحسن على فخذه الأخرى، ثم يضمهما، ثم يقول: اللهم ارحمهما فإني أرحمهما.
Bukhari narrated it in al-Adab (6003) from Abdullah bin Muhammad, who said, Arim told us, Mutamir bin Sulayman told us, narrating from his father, who said, I heard Abu Tamima narrating from Abu Uthman Nahdi, Abu Uthman narrating it, from Usama bin Zayd, and he mentioned it.