Ibn ‘Umar said, “We did not give up touching these two corners, the Yamani and the stone, whether it was difficult or easy, since I saw God’s messenger touch them." In a version by both of them Nafi’ said he saw Ibn ‘Umar touching the stone with his hand, after which he kissed his hand. He said, “I have not given it up since I saw God's messenger doing it." Bukhari and Muslim.
Source: sunnah.com
Other translations
Arabic
عَنِ ابْنِ عُمَرَ قَالَ: مَا تَرَكْنَا اسْتِلَامَ هَذَيْنِ الرُّكْنَيْنِ: الْيَمَانِي وَالْحَجَرِ فِي شِدَّةٍ وَلَا رخاء مُنْذُ رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يستلمهما وَفِي رِوَايَةٍ لَهُمَا: قَالَ نَافِعٌ: رَأَيْتُ ابْنَ عُمَرَ يَسْتَلِمُ الْحَجَرَ بِيَدِهِ ثُمَّ قَبَّلَ يَدَهُ وَقَالَ: مَا تَرَكْتُهُ مُنْذُ رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَفْعَله
sunnah.com