Sunan an-Nasa'i 1888
سنن النسائي#1888SahihSomething similar was narrated from Umm 'Atiyyah except, that he (the narrator) said:"Three times or five, or seven, or more than that, if you think that (is necessary)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 21:71