What is the oldest written source in this country that mentions this right?
Bahrain
Article 24 of the 1973 Bahrain Constitution states that “Freedom of the press, printing and publication shall be guaranteed in accordance with the conditions and procedure specified by the law.”
References:
“Bahrain Old Constitution (1973).” International Constitutional Law Project: https://www.servat.unibe.ch/icl/ba01000_.html