"O Abu abdur-Rahman, why do I only see you touching these two corners?" He said: "I heard the Messenger of Allah say: 'Touching them erases sins.' And I head him say: 'whoever circumambulates seven times, it is like freeing a slave.'" (Using translation from Nasāʾī 2919)   

يَا أَبَا عَبْدِ الرَّحْمَنِ مَا أَرَاكَ تَسْتَلِمُ إِلَّا هَذَيْنِ الرُّكْنَيْنِ قَالَ إِنِّي سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ «إِنَّ مَسْحَهُمَا يَحُطُّ الْخَطِيئَةَ»