After hearing the charge, the jury may either decide in court, or may retire for deliberation. If they do not agree without retiring, one or more officers must be sworn to keep them together in some private and convenient place, and not to permit any person to speak to or communicate with them, nor do so themselves, unless it be by order of the court, or to ask them whether they have agreed upon a verdict, and to return them into court when they have so agreed, or when ordered by the court.