Mishkat al-Masabih 10 The Rites of Pilgrimage كتاب المناسك 61

وَعَنِ الزُّبَيْرِ بْنِ عَرَبِيٍّ قَالَ: سَأَلَ رَجُلٌ ابنَ عمرَ عَنِ اسْتِلَامِ الْحَجَرِ فَقَالَ: رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَسْتَلِمُهُ وَيُقَبِّلُهُ. رَوَاهُ البُخَارِيّ

Az-Zubair b. ‘Arabi said that a man asked Ibn ‘Umar about touching the stone, and he replied that he had seen God s messenger touching it and kissing it. Bukhari transmitted it.