It is narrated from ‘Urwah bin Ja‘d (may Allah be pleased with him) that the Prophet ﷺ gave him a dinar so that he could buy a goat for him. He bought two goats with that dinar, then sold one goat for a dinar and returned the dinar as well as a goat to the Prophet ﷺ. So the Messenger of Allah ﷺ prayed for blessing in his trade, and after that, his situation was such that if he bought even dust, he would profit from it.
Hadith Referenceمسند الإمام الشافعي / كتاب البيوع / 1459