Sayyiduna Abu Hurairah (may Allah be pleased with him) narrated that the Noble Messenger (peace and blessings of Allah be upon him) forbade intercepting (trading) caravans, and that a townsman should not sell goods on behalf of a villager, and that a woman should not stipulate the divorce of her (religious or blood-related) sister, and that one should not bid against his brother’s bid. Likewise, he forbade najsh (artificially inflating prices) and tasriyah (concealing defects in goods).