Sunan Ibn Mājah 2519✓ 5Hasan
حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، وَمُحَمَّدُ بْنُ فُضَيْلٍ، عَنْ حَجَّاجٍ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَيُّمَا عَبْدٍ كُوتِبَ عَلَى مِائَةِ أُوقِيَّةٍ فَأَدَّاهَا إِلاَّ عَشْرَ أُوقِيَّاتٍ فَهُوَ رَقِيقٌ " .
It was narrated from 'Amr bin Shu'aib , from his father, from his grandfather that the Messenger of Allah (ﷺ) said:"Any slave who has made a contract to buy his freedom for one hundread Uqiyyah and pays it all except ten Uqiyyah; he is still a slave." (One Uqiyyah is equal to 40 Dirham)