Narrated Ali ibn AbuTalib:

Some slaves (of the unbelievers) went out to the Messenger of Allah ﷺ on the day of al-Hudaybiyyah before treaty. Their masters wrote to him saying: O Muhammad, they have not gone out to you with an interest in your religion, but they have gone out to escape from slavery. Some people said: They have spoken the truth, Messenger of Allah, send them back to them. The Messenger of Allah ﷺ became angry and said: I do not see your restraining yourself from this action), group of Quraysh, but that Allah send someone to you who strike your necks. He then refused to return them, and said: They are emancipated (slaves) of Allah, the Exalted.

حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ يَحْيَى الْحَرَّانِيُّ، حَدَّثَنِي مُحَمَّدٌ، - يَعْنِي ابْنَ سَلَمَةَ - عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، عَنْ أَبَانَ بْنِ صَالِحٍ، عَنْ مَنْصُورِ بْنِ الْمُعْتَمِرِ، عَنْ رِبْعِيِّ بْنِ حِرَاشٍ، عَنْ عَلِيِّ بْنِ أَبِي طَالِبٍ، قَالَ خَرَجَ عِبْدَانٌ إِلَى رَسُولِ اللَّهِ ﷺ - يَعْنِي يَوْمَ الْحُدَيْبِيَةِ - قَبْلَ الصُّلْحِ فَكَتَبَ إِلَيْهِ مَوَالِيهِمْ فَقَالُوا يَا مُحَمَّدُ وَاللَّهِ مَا خَرَجُوا إِلَيْكَ رَغْبَةً فِي دِينِكَ وَإِنَّمَا خَرَجُوا هَرَبًا مِنَ الرِّقِّ فَقَالَ نَاسٌ صَدَقُوا يَا رَسُولَ اللَّهِ رُدَّهُمْ إِلَيْهِمْ . فَغَضِبَ رَسُولُ اللَّهِ ﷺ وَقَالَ " مَا أُرَاكُمْ تَنْتَهُونَ يَا مَعْشَرَ قُرَيْشٍ حَتَّى يَبْعَثَ اللَّهُ عَلَيْكُمْ مَنْ يَضْرِبُ رِقَابَكُمْ عَلَى هَذَا " . وَأَبَى أَنْ يَرُدَّهُمْ وَقَالَ " هُمْ عُتَقَاءُ اللَّهِ عَزَّ وَجَلَّ " .