Hazrat Marwan Asghar (may Allah have mercy on him) narrates that I saw Sayyiduna Ibn Umar (may Allah be pleased with them both) make his mount face the Qiblah, then he sat facing it and began to urinate. I said, "O Abu Abdur Rahman, was this not prohibited?" He replied, "Why not. Indeed, it was prohibited in the open space. But when there is something screening between you and the Qiblah, then there is no harm."