عَن الْحسن عَن سَمُرَة عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «من ملك ذَا رحم محرم فَهُوَ حُرٌّ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ وَابْنُ مَاجَه
Translation

‘Amr b. Shu'aib, on his father’s authority, told that his grandfather reported God's Messenger as saying, “If anyone has agreed to let his slave buy his freedom for a hundred uqiyas and he pays them all but ten (or he said, ten dinars), and he is then unable to complete the amount, he remains a slave.” Tirmidhi, Abu Dawud and Ibn Majah transmitted it.