Sahih Bukhari Volume 1, Book 10, Hadith 788

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

Narrated By 'Ikrima : I saw a person praying at Muqam-lbrahim (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?"