أَخْبَرَنَا عِمْرَانُ بْنُ مُوسَى، قَالَ حَدَّثَنَا عَبْدُ الْوَارِثِ، قَالَ حَدَّثَنَا أَيُّوبُ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ مَا تَرَكْتُ اسْتِلاَمَ الْحَجَرِ فِي رَخَاءٍ وَلاَ شِدَّةٍ مُنْذُ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَسْتَلِمُهُ ‏.‏

It was narrated that Ibn Umar said: "Since I saw the Messenger of Allah touch it, I did not fail to touching the Stone whether it was easy or difficult." Translation Not Available

Book Ref: Sunan An Nisai Book 24 Hadith 2953
Web Ref:  Sunan An Nisai Vol 3 Book 24 Hadith 2956