Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrated: The Prophet (peace and blessings be upon him) said: "A vow is only valid in that by which Allah Almighty is obeyed; a vow concerning cutting off ties of kinship has no standing; and divorce or freeing a slave has no standing when a person does not own (the matter)."
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat, and added these words: "An oath concerning usurpation has no standing," and in it these words are omitted: "A vow concerning cutting off ties of kinship has no standing." The narrators of al-Mu'jam al-Kabir are thiqat (trustworthy).