(4) Prayer
كتاب الصلاة
(29a) Chapter: The manner in which one who is led in prayer by an Imam must follow him, and the rule applying to the one who is preceded by him - Section 1
(28) باب ما على المأموم من المتابعة وحكم المسبوق - الفصل الأول
Mishkat al-Masabih 1141 
Abu Huraira reported God’s Messenger as saying, “Does he who raises his head before the imam not fear that God may change his head into a donkey’s?” (Bukhari and Muslim.)
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَمَا يَخْشَى الَّذِي يَرْفَعُ رَأْسَهُ قَبْلَ الْإِمَامِ أَنْ يُحَوِّلَ اللَّهُ رَأْسَهُ رَأْسَ حمَار»
 مُتَّفَقٌ عَلَيْهِ  (الألباني)حكم :
Reference : Mishkat al-Masabih 1141
In-book reference : Book 4, Hadith 558