"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.'"
"Whoever swears by a religion other than Islam, telling a lie, will be as he said, and whoever kills himself with something, he will be punished with it in the Hereafter, and there is no vow concerning that which a man does not possess."
"My sister vowed to walk to the House of Allah, and she told me to ask the Messenger of Allah about that. So I asked the Prophet for her and he said: 'Let her walk, and let her ride.'"
"A woman traveled by sea and vowed to fast for a month, but she died before she could fast. Her sister came to the Prophet and told him about that, and he told her to fast on her behalf."
"Sa'd bin 'Ubadah asked the Messenger of Allah about a vow which his mother had sworn, but she died before she could fulfill it. The Messenger of Allah said: 'Fulfill it on her behalf.'"
"Sa'd bin 'Ubadah came to the Prophet and said: 'My mother died and she had sworn a vow, but she did not fulfill it.' He said: 'Fulfill it on her behalf.'"
أَخْبَرَنَا إِسْحَاقُ بْنُ مُوسَى، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ أَيُّوبَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنْ عُمَرَ، أَنَّهُ كَانَ عَلَيْهِ لَيْلَةٌ نَذَرَ فِي الْجَاهِلِيَّةِ يَعْتَكِفُهَا فَسَأَلَ رَسُولَ اللَّهِ صلى الله عليه وسلم فَأَمَرَهُ أَنْ يَعْتَكِفَ .
It was narrated from Ibn 'Umar, that 'Umar had vowed to spend a night in 'Itikaf during the Jahiliyyah. He asked the Messenger of Allah about that, and he ordered him to perform the 'Itikaf.