Musannaf Ibn Abi Shayba 7:243

Abu al-Ahwas narrated to us, from Mughirah, from Ibrahim, regarding a man who swore not to uphold his ties of kinship: He said: He should uphold his ties of kinship and offer expiation for his oath. Al-Sha'bi said: He should uphold his ties of kinship and not offer expiation for his oath. And if I were to command him to offer expiation for his oath, I would have commanded him to persist in his statement.