Nafi' bin Sarjis (may Allah have mercy on him) related that he went to Sayyiduna Abu Waqid al-Laythi (may Allah be pleased with him), who said: "When leading the people in prayer, the Messenger of Allah (peace and blessings be upon him) was among those who led the lightest prayer, and in his own (private) prayer he was among those who prayed the longest."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3299