It was narrated that Shurahbil bin Simt said:
I said to Ka'b bin Murrah, tell us a Hadith from the Messenger of Allah ﷺ, but be careful. He said: I heard the Messenger of Allah ﷺ say: “Whoever frees a Muslim man, he will be his ransom from the Fire; each of his bones will suffice (as a ransom) for each of his bones. Whoever frees two Muslim women, they will be his ransom from the Fire; each of their two bones will suffice (as a ransom) for each of his bones.”

حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ عَمْرِو بْنِ مُرَّةَ، عَنْ سَالِمِ بْنِ أَبِي الْجَعْدِ، عَنْ شُرَحْبِيلَ بْنِ السِّمْطِ، قَالَ قُلْتُ لِكَعْبٍ يَا كَعْبَ بْنَ مُرَّةَ حَدِّثْنَا عَنْ رَسُولِ اللَّهِ ﷺ وَاحْذَرْ . قَالَ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ " مَنْ أَعْتَقَ امْرَأً مُسْلِمًا كَانَ فِكَاكَهُ مِنَ النَّارِ يُجْزِئُ بِكُلِّ عَظْمٍ مِنْهُ عَظْمٌ مِنْهُ وَمَنْ أَعْتَقَ امْرَأَتَيْنِ مُسْلِمَتَيْنِ كَانَتَا فِكَاكَهُ مِنَ النَّارِ يُجْزِئُ بِكُلِّ عَظْمَيْنِ مِنْهُمَا عَظْمٌ مِنْهُ " .