Hadith 17:228
Yazid ibn Harun narrated to us, he said: Humayd al-Tawil narrated to us, from Anas, who said: I was with the boys, and the Prophet, peace be upon him, passed by us and greeted us. Then he sent me on an errand, and he sat by a wall or in a shade until I came to him and informed him of his errand. When I came to Umm Sulaym, she said: "What kept you today?" I said: "The Prophet, may Allah bless him and grant him peace, sent me on an errand." She said: "What is it?" I said: "It is a secret." She said: "Then guard the secret of the Messenger of Allah, may Allah bless him and grant him peace." He said: So I never told it to anyone at all.
حدثنا يزيد بن هارون قال حدثنا حميد الطويل عن أنس قال كنت مع الغلمان فمر علينا النبي عليه السلام فسلم علينا ثم بعثني في حاجة وجلس في جدار أو في ظل حتى أتيته فأبلغته حاجته فلما أتيت أم سليم قالت ما حبسك اليوم قلت [ بعثني ] النبي صلى الله عليه وسلم في حاجة قالت ما هي قلت إنها سر قالت فاحفظ سر رسول الله صلى الله عليه وسلم قال فما حدثت بها أحدا قط