What is the oldest written source in this country that mentions this right?
Republic of the Congo
The only mention of privacy rights today is that of the home in Article 20 of the 2015 Constitution (Constitute Project, “Congo (Republic of the) 2015”). The same right appeared in the 2001 Constitution in Article 14 (Constitute Project, “Congo (Republic of the) 2001”).
https://constituteproject.org/constitution/Congo_2015?lang=en https://constituteproject.org/constitution/Congo_2001?lang=en