Nasai

The purpose of mentioning the repetition is that some narrators have reported this narration as marfu‘ (a statement of the Messenger of Allah sallallahu alayhi wa sallam), while others have reported it as mawquf (a statement of the Companion radi Allahu anhu). This difference is not harmful because a mawquf narration does not negate the marfu‘, and it is correct for the narration to be transmitted in both ways, provided that the chains of transmission are free from weakness. It is as if the Messenger of Allah sallallahu alayhi wa sallam said it, and the Companion also stated the same thing.