(10) The Rites of Pilgrimage
كتاب المناسك
(11a) Chapter: The Sermon on the day of Sacrifice, throwing Pebbles on the tashriq days, and taking Farewell of the Ka`ba - Section 1
(10) باب خطبة يوم النحر - الفصل الأول
Mishkat al-Masabih 2660 
Wabara said he asked Ibn ‘Umar when he should throw pebbles at the jamras, to which he replied, “Throw them when your imam does so.” He repeated the question and received the reply, “We used to wait for the proper time, and when the sun passed the meridian we threw them.” Bukhari transmitted it.
وَعَن وَبرةَ قَالَ: سَأَلْتُ ابْنَ عُمَرَ: مَتَى أَرْمِي الْجِمَارَ؟ قَالَ: إِذَا رَمَى إِمَامُكَ فَارْمِهِ فَأَعَدْتُ عَلَيْهِ الْمَسْأَلَةَ. فَقَالَ: كُنَّا نَتَحَيَّنُ فَإِذَا زَالَتِ الشَّمْسُ رمينَا. رَوَاهُ البُخَارِيّ
 صَحِيح  (الألباني)حكم :
Reference : Mishkat al-Masabih 2660
In-book reference : Book 10, Hadith 151