Sayyiduna Kardam bin Sufyan (may Allah be pleased with him) narrates that he asked the Prophet (peace and blessings be upon him) about a vow he had made in the Days of Ignorance (Jahiliyyah). The Prophet (peace and blessings be upon him) asked him: "Was it for an idol or for a stone altar (nusub)?" He replied: "No, rather it was for Allah Almighty." The Prophet (peace and blessings be upon him) said: "Then fulfil for Allah Almighty what you dedicated to Allah Almighty; slaughter an animal seeking His reward, and fulfil your vow."
Ahmad recorded it; its chain contains a narrator who could not be identified.