Musannaf Ibn Abi Shaybah 23629 — The swearing that was forbidden

Sayyiduna Qays (may Allah be pleased with him) said: We used to trade in Madinah and called ourselves samasirah (brokers). Then the Prophet (peace and blessings be upon him) came to us and called us by a name better than the one we used for ourselves. He (peace and blessings be upon him) said: "O traders! Idle talk and oath-taking occur in this business, so make up for it with charity."