صَحِيحُ مُسْلِمٍ
Sahih Muslim 1267 c
The Book of Pilgrimage
It is recommended to touch the two Yemeni Corners in Tawaf and not the other two corners
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ، ذَكَرَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ لاَ يَسْتَلِمُ إِلاَّ الْحَجَرَ وَالرُّكْنَ الْيَمَانِيَ.
Nafi' reported on the authority of 'Abdullah (Allah be pleased with him) that Allah's Messenger (ﷺ) did not touch but the Stone and the Yamani corner.
Sahih Muslim, 1267 cSahihصحيح