Abu Dharr (RAA) narrated, I asked the Messenger of Allah (ﷺ) 'Which action is the most excellent?' He replied, "Faith in Allah and Jihad in His Cause." I then asked, 'Which slaves are the most excellent (for the purpose of emancipating them)' and he replied, "Those whose prices are the highest and are the most valuable to their owners." Agreed upon. (IT)
English reference (IT): Book 15, Hadith 1465 (IT)
Arabic reference (IT): Book 15, Hadith 1421 (IT)