Tex. Code Crim. Proc. art. 36.06

Witnesses, when placed under rule, shall be instructed by the court that they are not to converse with each other or with any other person about the case, except by permission of the court, and that they are not to read any report of or comment upon the testimony in the case while under rule. The officer who attends the witnesses shall report to the court at once any violation of its instructions, and the party violating the same shall be punished for contempt of court.