Al-Adab Al-Mufrad: Behaviour with people – Hadith No. 1157 — I was serving the Messenger of Allah, may Allah bless him and grant him peace… (Hadith No. 1157)

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.'"

Explanation:

Reference: Al-Adab Al-Mufrad, Behaviour with people, Hadith No. 1157