It is narrated from Yazid bin Abdullah bin Qasit that Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) sent one of his slaves with gold or silver. He engaged in a currency exchange transaction and made it on credit. When he returned, Sayyiduna Ibn Umar (may Allah be pleased with them both) severely beat him and said: Go, bring my property back and do not engage in a currency exchange transaction.

Narrated from Sayyiduna Abu Mas’ud Uqbah bin ‘Amr (may Allah be pleased with him): I was beating my slave when suddenly I heard a voice from behind me:“Abu Mas’ud! Know that Allah has more power over you than you have over him.”I turned around and saw that it was the Messenger of Allah (peace and blessings be upon him). I said: O Messenger of Allah! I set him free for the sake of Allah. The Prophet (peace and blessings be upon him) said:“If you had not done so, the fire of Hell would certainly have touched you.”Or he said:“The fire would certainly have engulfed you.”