Hasan al-Basri (may Allah have mercy on him) says that once Umar al-Faruq (may Allah be pleased with him) intended to prohibit Hajj Tamattu', so Ubayy ibn Ka'b (may Allah be pleased with him) said to him, "You cannot do that. We performed Hajj Tamattu' with the Prophet (peace and blessings be upon him), but the Prophet (peace and blessings be upon him) did not prohibit us from it." Thus, Umar (may Allah be pleased with him) refrained from this intention. Then he intended to prohibit striped Yemeni cloaks and garments because urine stains were applied to them, so Ubayy ibn Ka'b (may Allah be pleased with him) said to him, "You cannot do this either, because these cloaks were worn by the Prophet (peace and blessings be upon him) himself, and we also wore them during his blessed era."