Ibn 'Umar reported that the Messenger of Allah (ﷺ), Abu Bakr and 'Umar used to observe the two 'Id prayers before the sermon. (IT)
Reference (IT): Sahih Muslim 888 (IT)
In-book reference (IT): Book 8, Hadith 8 (IT)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1930 (IT)