Habib bin Ubayd (may Allah have mercy on him) said: I saw Sayyiduna al-Miqdam bin Ma'di Karib (may Allah be pleased with him) sitting in the market, while a slave girl of his was selling milk and he sat taking the dirhams. He was asked about that, and he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "In the last times, people will not be able to manage without dirhams and dinars; by means of them a man will maintain both his religion and his worldly life."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17794