وَ رَوَى عَمْرُو بْنُ شِمْرٍ عَنْ جَابِرٍ عَنْ أَبِي جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ قَالَ: سَأَلْتُهُ عَنِ اَلْمُكَاتَبِ يُشْتَرَطُ عَلَيْهِ إِنْ عَجَزَ فَهُوَ رَدٌّ فِي اَلرِّقِّ فَعَجَزَ قَبْلَ أَنْ يُؤَدِّيَ شَيْئاً قَالَ "لاَ يُرَدُّ فِي اَلرِّقِّ حَتَّى يَمْضِيَ لَهُ ثَلاَثُ سِنِينَ وَ يُعْتَقُ مِنْهُ مِقْدَارُ مَا أَدَّى صَدْراً فَإِذَا أَدَّى صَدْراً فَلَيْسَ لَهُمْ أَنْ يَرُدُّوهُ فِي اَلرِّقِّ".
Amr ibn Shimr narrated from Jabir, from Abu Ja'far Imam Muhammad ibn Ali Al-Baqir (a.s), who said: I asked him about a mukatab (a slave under a contract of emancipation) who had a condition stipulated that if he failed to make payments, he would return to slavery. What if he failed before paying anything? Imam (a.s) said: "He does not return to slavery until three years have passed. Whatever portion he has already paid counts toward his emancipation. If he has made partial payments, they cannot return him to slavery."