Hadith 11:6
Samura b. Jundub reported God’s Messenger as saying, “The most excellent sadaqa is intercession for which a slave is set free.” Baihaqi transmitted it in Shu'ab al-iman .
وَعَن سَمُرَةَ بْنِ جُنْدُبٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَفْضَلُ الصَّدَقَةِ الشَّفَاعَةُ بِهَا تُفَكُّ الرَّقَبَة» . رَوَاهُ الْبَيْهَقِيّ فِي «شعب الْإِيمَان»
Original Reference: Mishkat al-Masabih 3387