In the name of Allah, the Beneficent, the Merciful
An-Nawawi records in his book, Riyad us-Saliheen:
فَلَا اقْتَحَمَ الْعَقَبَةَ وَمَا أَدْرَاكَ مَا الْعَقَبَةُ فَكُّ رَقَبَةٍ
But he has not broken through the difficult path, and what will make you know what is the difficult path? It is the freeing of a slave.
Surah Al-Balad 90:11-13
Abu Huraira reported: The Prophet, peace and blessings be upon him, said:
مَنْ أَعْتَقَ رَقَبَةً مُسْلِمَةً أَعْتَقَ اللَّهُ بِكُلِّ عُضْوٍ مِنْهُ عُضْوًا مِنْ النَّارِ حَتَّى فَرْجَهُ بِفَرْجِهِ
Whoever frees a Muslim slave, then Allah will free every limb of his body from the Hellfire, even his private parts.
Source: Sahih Bukhari 6337, Grade: Sahih
Abu Dharr reported: I said, “O Messenger of Allah, which deed is best?” The Messenger of Allah, peace and blessings be upon him, said:
الْإِيمَانُ بِاللَّهِ وَالْجِهَادُ فِي سَبِيلِهِ
Faith in Allah and striving in His way.
I said, “Which slave is the best to free?” He said:
أَنْفَسُهَا عِنْدَ أَهْلِهَا وَأَكْثَرُهَا ثَمَنًا
One who is valuable to his master and whose price is high.
Source: Sahih Muslim 84, Grade: Sahih
Abu Musa Al-Ashari reported: The Prophet, peace and blessings be upon him, said:
أَطْعِمُوا الْجَائِعَ وَعُودُوا الْمَرِيضَ وَفُكُّوا الْعَانِيَ
Feed the hungry, visit the sick, and set the slaves free.
Source: Sahih Bukhari 5058, Grade: Sahih
Success comes from Allah, and Allah knows best.