Ibn Sarjis says: We visited Sayyiduna Abu Waqid al-Laythi (may Allah be pleased with him) during the illness in which he died, and we heard him say that the Prophet (peace and blessings be upon him) kept the prayer brief when leading people, and when praying by himself he prayed longer than anyone.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5279