Sahih al-Bukhari, Hadith 1609 ⓘ
Narrated Salim bin `Abdullah that his father said: "I have not seen the Prophet touching except the two Yemenite Corners (i.e. the ones facing Yemen)."
حَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا لَيْثٌ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِيهِ ـ رضى الله عنهما ـ قَالَ لَمْ أَرَ النَّبِيَّ صلى الله عليه وسلم يَسْتَلِمُ مِنَ الْبَيْتِ إِلاَّ الرُّكْنَيْنِ الْيَمَانِيَيْنِ.
also referenced under: Book 25, Hadith 95 (In-Book) & Volume 2, Book 26, Hadith 678 (USC-MSA)