And whosoever toucheth one that is slain with a sword in the
 open fields
 That is killed by another, that dies a violent death, either by the sword or other means; one that touched such an one was unclean, or that touched the sword with which he was slain, as the Targum of Jonathan adds: "or a dead body": that dies a natural death, or suddenly, or in any way: 
 or a bone off a man;
 dug out of a grave, and lying by itself: 
 or a grave;
 the Targum adds, either the covering or side of a grave: 
 shall be unclean seven days;
 all which has respect to the defiling nature of sin, which is the cause of death and the grave.