It was narrated from Samurah bin Jundab that the Messenger of Allah (ﷺ) said:
"The contractual obligation regarding a slave lasts for three days." (1) (RU)
English reference (RU): Vol. 3, Book 12, Hadith 2244 (RU)
Arabic reference (RU): Book 12, Hadith 2329 (RU)