Mukhtasar Muslim (Abridged) 958 — Prohibition of swearing oaths

It is narrated from Sayyiduna Abu Qatadah Ansari (may Allah be pleased with him) that he heard the Messenger of Allah (peace and blessings of Allah be upon him) say: "Avoid excessive swearing in trade, for it may promote the sale of goods but then erases (the blessing from it)."