Muhammad bin Abdullah bin Zaid bin Abdur-Rabbah said: My father Abdullah bin Zaid said: When the Messenger of Allah (ﷺ) ordered for the bell (naqus) . . . and then narrated the aforementioned hadith.
Hadith Referenceسنن دارمي / من كتاب الصللاة / 1222
(Explanation of Ahadith 1220 to 1222) From all these narrations, the beginning of the adhan, its legislation, and its manner are established. Also, except for the words of the iqamah («قد قامت الصلاة» and «اللّٰه أكبر»), the rest of the phrases are to be said singly, that is, each phrase is to be said once.
And through a dream, the permissibility or legislation (of something) will be established only in the presence of the Messenger of Allah (sallallahu alayhi wa sallam), not after his passing.
Also, it is established that the dream of a believer is true.