Oaths and Vows
كتاب الأيمان والنذور
Chapter 30: If somebody dies without fulfiling a vow
A man came to the Prophet (ﷺ) and said to him, "My sister vowed to perform the Hajj, but she died (before fulfilling it)." The Prophet (ﷺ) said, "Would you not have paid her debts if she had any?" The man said, "Yes." The Prophet (ﷺ) said, "So pay Allah's Rights, as He is more entitled to receive His rights."
Chapter 31: To vow for something not possessed, and for something sinful
The Prophet (ﷺ) said, "Allah is not in need of this man) torturing himself," when he saw the man walking between his two sons (who were supporting him).
Chapter 32: If somebody has vowed that he will observe Saum
that he was asked about a man who had vowed that he would fast all the days of his life then the day of `Id al Adha or `Id-al-Fitr came. `Abdullah bin `Umar said: You have indeed a good example in Allah's Messenger (ﷺ). He did not fast on the day of `Id al Adha or the day of `Id-al-Fitr, and we do not intend fasting on these two days.
I was with Ibn `Umar when a man asked him, "I have vowed to fast every Tuesday or Wednesday throughout my life and if the day of my fasting coincided with the day of Nahr (the first day of `Id-al- Adha), (What shall I do?)" Ibn `Umar said, "Allah has ordered the vows to be fulfilled, and we are forbidden to fast on the day of Nahr." The man repeated his question and Ibn `Umar repeated his former answer, adding nothing more.
Chapter 33: Can the land, sheep, farms and one's belongings be included in vows and oaths?
We went out in the company of Allah's Messenger (ﷺ) on the day of (the battle of) Khaibar, and we did not get any gold or silver as war booty, but we got property in the form of things and clothes. Then a man called Rifa`a bin Zaid, from the tribe of Bani Ad-Dubaib, presented a slave named Mid`am to Allah's Apostle. Allah's Messenger (ﷺ) headed towards the valley of Al-Qura, and when he was in the valley of Al- Qura an arrow was thrown by an unidentified person, struck and killed Mid`am who was making a she-camel of Allah's Messenger (ﷺ) kneel down. The people said, "Congratulations to him (the slave) for gaining Paradise." Allah's Messenger (ﷺ) said, "No! By Him in Whose Hand my soul is, for the sheet which he stole from the war booty before its distribution on the day of Khaibar, is now burning over him." When the people heard that, a man brought one or two Shiraks (leather straps of shoes) to the Prophet. The Prophet (ﷺ) said, "A Shirak of fire, or two Shiraks of fire."