Sayyiduna Uqbah bin Amir (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him): "The guarantee against a slave's defects lasts four nights."
Hisham said: Qatadah said: The people of Madinah mention three nights.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10753