The Prophet (ﷺ) said, "The Wala' is for the manumitted (of the slave).
Sahih al-Bukhari Book 85, Hadith 29
← Previous Hadith I bought Barira (a female slave). The Prophet (ﷺ) said (to me), "Buy her as the Wala' is for the manumitted." Once she was given a sheep (in charity). The Prophet (ﷺ) said, "It (the sheep) is a charitable gift for her (Barira) and a gift for us." Al-Hakam said, "Barira's husband was a free man." Ibn `Abbas said, 'When I saw him, he was a slave."

Sahih al-Bukhari Book 85, Hadith 28 Next Hadith → The Muslims did not free slaves as Sa'iba, but the People of the Pre-lslamic Period of Ignorance used to do so.

Sahih al-Bukhari Book 85, Hadith 30