´It was narrated that Nafi said:` "Abdullah, may Allah be pleased with him, said: "I have not failed to touch these two corners since I saw the Messenger of Allah touching them, the Yemeni Corner and Black Stone, either when it is difficult or when it is easy.'"
Explanation & Benefits
Hafiz Muhammad Ameen
For a detailed explanation of the relevant issue, see Hadith number 2918 and 2949.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 2955