Sahih Muslim 2050
صحيح مسلم#2050SahihAta' reported that Ibn 'Abbas sent (him) to Ibn Zubair at the commencement of the oath of allegiance to him (for Caliphate saying):As there is no Adhan on 'Id-ul-Fitr, so you should not pronounce it. Ibn Zubair did not pronounce Adhan on that day. He (Ibn 'Abbas) also sent him (with this message) that sermon (is to be delivered) after the prayer, and thus it was done. So lbn Zubair observed prayer before Khutba
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 8:6