Hadith 8:2356
Abu Bakr narrated to us, he said: Ubaydullah narrated to us, from Uthman ibn al-Aswad, from Mujahid, who said: The two corners that are adjacent to the Black Stone are not to be touched.
حدثنا أبو بكر قال حدثنا عبيد الله عن عثمان بن الأسود عن مجاهد قال الركنان اللذان يليان الحجر لا يستلمان