I do not know whether the following words are part of the tradition of the Prophet ﷺ or Nafi' told them himself: "Otherwise he will be emancipated to the extent of the first man's share."
عَنِ النَّبِيِّ ﷺ بِهَذَا الْحَدِيثِ قَالَ أَيُّوبُ فَلاَ أَدْرِي هُوَ فِي الْحَدِيثِ عَنِ النَّبِيِّ ﷺ أَوْ شَىْءٌ قَالَهُ نَافِعٌ وَإِلاَّ عَتَقَ مِنْهُ مَا عَتَقَ