The Book of Pilgrimage
15/40. Chapter:
It is recommended to touch the two Yemeni Corners in Tawaf and not the other two corners
Sahih Muslim
وَحَدَّثَنِي أَبُو الطَّاهِرِ، أَخْبَرَنَا ابْنُ وَهْبٍ، أَخْبَرَنَا عَمْرُو بْنُ الْحَارِثِ، أَنَّ قَتَادَةَ بْنَ، دِعَامَةَ حَدَّثَهُ أَنَّ أَبَا الطُّفَيْلِ الْبَكْرِيَّ حَدَّثَهُ أَنَّهُ، سَمِعَ ابْنَ عَبَّاسٍ، يَقُولُ لَمْ أَرَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَسْتَلِمُ غَيْرَ الرُّكْنَيْنِ الْيَمَانِيَيْنِ .
Ibn 'Abbas (Allah be pleased with them) is reported to have said that he did not see Allah's Messenger (ﷺ) touching other than the Yamani corners.
Reference : Sahih Muslim 1269In-book reference : Book 15, Hadith 272USC-MSA web (English) reference : Book 7, Hadith 2911