Sahih al-Bukhari 787
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · Itmam At-Takbir (i.e., to end the number of Takbir, or to say the Takbir perfectly) on prostrating. [See Fath Al-Bari]
Narrated `Ikrima:
حَدَّثَنَا عَمْرُو بْنُ عَوْنٍ ، قَالَ حَدَّثَنَا هُشَيْمٌ ، عَنْ أَبِي بِشْرٍ ، عَنْ عِكْرِمَةَ ، قَالَ رَأَيْتُ رَجُلاً عِنْدَ الْمَقَامِ يُكَبِّرُ فِي كُلِّ خَفْضٍ وَرَفْعٍ وَإِذَا قَامَ وَإِذَا وَضَعَ، فَأَخْبَرْتُ ابْنَ عَبَّاسٍ ـ رضى الله عنه ـ قَالَ أَوَلَيْسَ تِلْكَ صَلاَةَ النَّبِيِّ صلى الله عليه وسلم لاَ أُمَّ لَكَ.
I saw a person praying at Muqam-Ibrahim (the place of Abraham by the Ka`ba) and he was saying Takbir on every bowing, rising, standing and sitting. I asked Ibn `Abbas (about this prayer). He admonished me saying: "Isn't that the prayer of the Prophet?"