حَدَّثَنَا أَبُو نُعَيْمٍ، قَالَ: حَدَّثَنَا سُلَيْمَانُ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ: خَدَمْتُ رَسُولَ اللهِ صلى الله عليه وسلم يَوْمًا، حَتَّى إِذَا رَأَيْتُ أَنِّي قَدْ فَرَغْتُ مِنْ خِدْمَتِهِ قُلْتُ: يَقِيلُ النَّبِيُّ صلى الله عليه وسلم، فَخَرَجْتُ مِنْ عِنْدِهِ، فَإِذَا غِلْمَةٌ يَلْعَبُونَ، فَقُمْتُ أَنْظُرُ إِلَيْهِمْ إِلَى لَعِبِهِمْ، فَجَاءَ النَّبِيُّ صلى الله عليه وسلم فَانْتَهَى إِلَيْهِمْ فَسَلَّمَ عَلَيْهِمْ، ثُمَّ دَعَانِي فَبَعَثَنِي إِلَى حَاجَةٍ، فَكَانَ فِي فَيْءٍ حَتَّى أَتَيْتُهُ. وَأَبْطَأْتُ عَلَى أُمِّي، فَقَالَتْ: مَا حَبَسَكَ؟ قُلْتُ: بَعَثَنِي النَّبِيُّ صلى الله عليه وسلم إِلَى حَاجَةٍ، قَالَتْ: مَا هِيَ؟ قُلْتُ: إِنَّهُ سِرٌّ لِلنَّبِيِّ صلى الله عليه وسلم، فَقَالَتِ: احْفَظْ عَلَى رَسُولِ اللهِ صلى الله عليه وسلم سِرَّهُ، فَمَا حَدَّثْتُ بِتِلْكَ الْحَاجَةِ أَحَدًا مِنَ الْخَلْقِ، فَلَوْ كُنْتُ مُحَدِّثًا حَدَّثْتُكَ بِهَا.
Anas said, "I was serving the Messenger of Allah, may Allah bless him and grant him peace, one day. When I thought I had finished serving him, I said, 'The Prophet, may Allah bless him and grant him peace, is having a midday nap.' So I left him and there were some children playing. I stood looking at them and their game. The Prophet, may Allah bless him and grant him peace, came out, and came up to them and greeted them. Then he called me and sent me to get something he needed. He remained in the shade until I came back to him. I was late for my mother and she and he asked, 'What kept you?' I replied, The Prophet, may Allah bless him and grant him peace, sent me for something he needed.' 'What was it?' she asked. I replied, 'It is a secret of the Prophet, may Allah bless him and grant him peace.' She said, Keep the secret of the Messenger of Allah, may Allah bless him and grant him peace.' I did not tell anyone that secret. If I had told it, I would have told it to her.'"
Cited in Al-Adab al-Mufrad (No. 1154).