Someone said to Ibn Umar, "Our imam prolongs the prayer."Ibn Umar replied, "Two rakahs of the prayer of the Messenger of Allah ﷺ were lighter than, or equal to, a single rakah of this man's prayer."
حدثنا محمد بن جعفر حدثنا شعبة
قيل لابن عمر إن إمامنا يطيل الصلاة فقال ابن عمر ركعتان من صلاة رسول الله ﷺ أخف أو مثل ركعة من صلاة هذا
Its chain of transmission is sahih. Hayan Bariqi is Hayan bin Iyas, and he is trustworthy. Ibn Hibban mentioned him among the trustworthy narrators, and Bukhari included his biography in al-Kabir 2/1/50, saying, "He heard from Ibn Umar." Hayan is with a fatha on the plain ha and a doubled ya.Haythami mentioned this hadith in Majma al-Zawaid 2:73–74 in a shortened form similar to this, and said, "Tabarani related it in al-Kabir, and its narrators are trustworthy." He failed to mention this narration from the Musnad.