At the end of the episode as Micheal enters to view the body bags of dead angels, the body bag directly behind his legs moves.
Metal swords did not exist in 1900 BC. First metal swords were from 17th century BC, and those were bronze swords, not iron, and particularly not steel swords, as were those seen in the opening scene. Also, on the sand there are bell peppers which were first brought from South America in 15th century - some 34 centuries later.