What are hadiths about vow? Examples of hadiths about vow…
According to Ibn ʿAbbas (ra), a woman had vowed to make the Hajj, but she died before fulfilling her vow. So, her brother went to the Prophet (saw) and asked him what should be done. He said, “Do you think that if your sister owed a debt you would pay it off?” He said, “Yes.” He said, “Then pay the debt to Allah, for He is more deserving that vows to Him should be fulfilled.” (al-Nasaʾi, Manasik al-hajj, 7)
According to ʿAʾisha (ra), the Prophet (saw) said, “Whoever vows that he will be obedient to Allah should be obedient to Him; and whoever vows that he will disobey Allah, should not disobey Him.” (al-Bukhari, al-Ayman wa ‘l-nudhur, 28)
According to Ibn ʿAbbas (ra), the Prophet (saw) said, “. . . whoever makes a vow that he can fulfill should do so!” (Ibn Maja, al-Kaffarat, 17)
According to Abu Hurayra (ra), the Prophet (saw) said, “The vow does not bring anything near to a person which Allah has not ordained for him, but (at times) the vow coincides with fate, and in this way something is extracted from the miser, which the miser did not want to be extracted.” (Muslim, al-Nadhr, 7)
Source: Presidency Of Religious Affairs The Turkey, Islam Through Hadiths