(4) Prayer
كتاب الصلاة
(29c) 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 3
(28) باب ما على المأموم من المتابعة وحكم المسبوق - الفصل الثالث
Mishkat al-Masabih 1149 
He said:
If anyone raises and lowers his head before the imam, his forelock is in the devil’s hand. Malik transmitted it.
وَعنهُ قَالَ: الَّذِي يَرْفَعُ رَأْسَهُ وَيَخْفِضُهُ قَبْلَ الْإِمَامِ فَإِنَّمَا ناصيته بيد الشَّيْطَان ". رَوَاهُ مَالك
 ضَعِيف  (الألباني)حكم :
Reference : Mishkat al-Masabih 1149
In-book reference : Book 4, Hadith 566