It is recommended to touch the two Yemeni Corners in Tawaf and not the other two corners
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا اللَّيْثُ، ح وَحَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا لَيْثٌ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ قَالَ لَمْ أَرَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَمْسَحُ مِنَ الْبَيْتِ إِلاَّ الرُّكْنَيْنِ الْيَمَانِيَيْنِ .
Ahdullah b. Umar (reported) that he had not seen Allah's Messenger (way peace he upon him) touching anything in the House, except the two Yamani corners.