Exodus 19:23
But Moses responded to the Lord, “The people cannot come up Mount Sinai, since You warned us: Put a boundary around the mountain and consider it holy.”
Exodus 19:12
                            Put boundaries for the people all around the mountain and say: Be careful that you don’t go up on the mountain or touch its base. Anyone who touches the mountain will be put to death.
Joshua 3:4-5
                            But keep a distance of about 1,000 yards
Treasury of Scripture Knowledge
Summary
                            And Moses said unto the LORD, The people cannot come up to mount Sinai: for thou chargedst us, saying, Set bounds about the mount, and sanctify it.                        
                    Set bounds
Bible References
Set bounds
                                        Exodus 19:12                                        
                                                                                                                                Put boundaries for the people all around the mountain and say: Be careful that you don’t go up on the mountain or touch its base. Anyone who touches the mountain will be put to death.  
                                    
                                        Joshua 3:4                                        
                                                            
                        But keep a distance of about 1,000 yards between yourselves and the ark. Don’t go near it, so that you can see the way to go, for you haven’t traveled this way before.”