سنن أبي داود

Narrated Nafi' ibn AbdulHarith:

I went out with the (Messenger of Allah (ﷺ) until I entered a garden, he said: Keep on closing the door. The door was then closed. I then said: Who is there ? He then narrated the rest of the tradition.

Abu Dawud said: That is to say, the tradition of Abu Musa al-Ash'ari. In this version he said: "He then knocked at the door."