Sunan an-Nasa'i 630
سنن النسائي#630SahihIt was narrated from Abu Mahdhurah that the Messenger of Allah (S.A.W) taught him the Adhan with nineteen phrases and the Iqamah with seventeen phrases, then Abu Mahdhurah counted them as nineteen and seventeen
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahHasan Sahih
Al-AlbaniHasan Sahih
Zubair Ali ZaiSahih
In-book reference: 7:5