Hadith 2937
Hakim b. Hizam said God's Messenger sent him with a dinar to buy a sacrificial animal for him. He bought a sheep for a dinar, sold it for two, came back, bought a sacrificial animal for a dinar, and brought it along with the extra dinar which he had gained. God’s Messenger gave the dinar as sadaqa and asked a blessing on him in his trading. Tirmidhi and Abu Dawud transmitted it.
وَعَن حَكِيم بن حزَام أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بَعَثَ مَعَهُ بِدِينَارٍ لِيَشْتَرِيَ لَهُ بِهِ أُضْحِيَّةً فَاشْتَرَى كَبْشًا بِدِينَارٍ وَبَاعَهُ بِدِينَارَيْنِ فَرَجَعَ فَاشْتَرَى أُضْحِيَّةً بِدِينَارٍ فَجَاءَ بِهَا وَبِالدِّينَارِ الَّذِي اسْتَفْضَلَ من الْأُخْرَى فَتصدق رَسُول الله صلى بِالدِّينَارِ فَدَعَا لَهُ أَنْ يُبَارَكَ لَهُ فِي تِجَارَته. رَوَاهُ التِّرْمِذِيّ