"The Messenger of Allab passed by a man who was leading another man with something that he had stipulated in a vow. The Prophet took it and broke it, and he said: 'It is a vow.'" (Sahih) Chatper 136. It Is Permissible To Speak During Tawaf (Using translation from Nasāʾī 2921)   

مَرَّ رَسُولُ اللهِ ﷺ بِرَجُلٍ يَقُودُ رَجُلًا فِي نَذْرٍ فَتَنَاوَلَهُ النَّبِيُّ ﷺ فَقَطَعَهُ فَقَالَ «إِنَّهُ نَذَرَ»  

"The Prophet passed by a man who was circumambulating the Ka'bah, led by another man with a reign in his nose. The Prophet took him by the hand and commanded him to lead him by his hand." Ibn Juraij said: "Sulaiman told me that Tawus told him, from Ibn 'Abbas, that the Prophet passed by him when he was circumambulating the Ka'bah, and a man had tied his hand to another man with some string or thread or whatever. The Prophet cut it with his hand then said: 'Lead him with your hand.'" (Using translation from Nasāʾī 3811)  

أَنَّ النَّبِيَّ ﷺ مَرَّ يَعْنِي بِرَجُلٍ وَهُوَ يَطُوفُ بِالْكَعْبَةِ يَقُودُهُ إِنْسَانٌ بِخِزَامَةٍ فِي أَنْفِهِ فَقَطَعَهُ النَّبِيُّ ﷺ بِيَدِهِ ثُمَّ «أَمْرَهُ أَنْ يَقُودَهُ بِيَدِهِ» قَالَ ابْنُ جُرَيْجٍ وَأَخْبَرَنِي سُلَيْمَانُ أَنَّ طَاوُسًا أَخْبَرَهُ عَنِ ابْنِ عَبَّاسٍ أَنَّ النَّبِيَّ ﷺ مَرَّ وَهُوَ يَطُوفُ بِالْكَعْبَةِ بِإِنْسَانٍ وَقَدْ رَبَطَ يَدَهُ بِإِنْسَانٍ آخَرَ بِسَيْرٍ أَوْ بِخَيْطٍ أَوْ بِشَيْءٍ غَيْرِ ذَلِكَ فَقَطَعَهُ النَّبِيُّ ﷺ بِيَدِهِ ثُمَّ قَالَ «قُدْهُ بِيَدِهِ»