Sayyiduna Ubadah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "Whoever sells a slave who has property or who owes a debt, the payment of the debt is the seller's responsibility, unless the seller has stipulated a condition on the buyer, in which case the ruling will differ."
Al-Tabarani recorded it in al-Mu'jam al-Kabir; Ishaq bin Yahya bin Ubadah did not meet his grandfather Sayyiduna Ubadah (may Allah be pleased with him).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6516