When the case is finally submitted to the jury, they may decide in court or retire for deliberation. If they retire, they must be kept together, in some convenient place, under charge of an officer, until they agree upon a verdict or be discharged by the court, subject to the discretion of the court, to permit them to separate temporarily at night, and at their meals. The officer having them under his charge shall not suffer any communication to be made to them, or make any himself, except to ask them if they are agreed upon their verdict, unless by order of the court; and he shall not, before their verdict is rendered, communicate to any person the state of their deliberations, or the verdict agreed upon.