وَعَنِ ابْنِ عُمَرَ قَالَ: لَمْ أَرَ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَسْتَلِمُ من الْبَيْت إِلَّا الرُّكْنَيْنِ اليمانيين

Ibn ‘Umar said that he had not seen the Prophet touching anything in the House but the two Yamani corners (The corner containing the Black Stone and the Yamani corner to the south-east which, as is usually held, should be touched but not kissed. They are both held to be on the foundations laid by Abraham). Bukhari and Muslim.