Abu Dawud
Prayer
Book Number: 002 / Hadith Number: 887
Narated By Anas ibn Malik : I did not offer behind anyone after the Apostle of Allah (pbuh) a prayer like the prayer offered by the Apostle of Allah (pbuh) than this youth, i.e. Umar ibn AbdulAziz. We estimated reciting glorification ten times in his bowing, and in his prostration ten times.