Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrated: A man came to the Prophet (peace and blessings be upon him) and asked him for a ruling: in an oath he had sworn he had made a sacrifice obligatory upon himself. The Prophet (peace and blessings be upon him) told him the ruling that he must sacrifice a camel, and he rebuked the man against doing such a thing again.
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains a narrator, al-Qasim bin Fayyad, whom Imam Abu Dawud declared thiqah (trustworthy) and Yahya bin Ma'in declared da'if (weak); the rest of its narrators are thiqat (trustworthy).