What is the oldest written source in this country that mentions this right?
Sudan
Sudan’s Constitution of 1973 is the first document to protect freedom of expression in the country’s history. Article 48 specifically defines the right.
“The Permanent Constitution of the Sudan.” World Constitutions Illustrated, Heinonline. Accessed July 13, 2023. https://heinonline.org/HOL/P?h=hein.cow/zzsd0013&i=1