The majority of the Amarna letters were written to the pharaoh of Ancient Egypt and the only reference to Naribta is a letter by Biridiya of Magidda, EA 365, entitled: "Furnishing corvée workers", (EA is for 'el Amarna').
EA 365, Biridiya letter no. 7 of 7 "Furnishing corvée workers"
"Say [to the ki]ng-(i.e. pharaoh), my lord and my [Su]n: Message of Biridiya, the loyal servant of the king. I fall at the feet of the king, my lord and my Sun, 7 times and 7 times.
"May the king, my lord, take cognizance of his servant and his city. In fact, only I am cultivating:ah-ri-šuin Šunama-(Shunem), and only I am furnishing corvée workers. But consider the mayors that are near me. They do not act as I do. They do not cultivate in Šunama, and they do not furnish corvée workers. Only I–ia8-hu-du-un-ni(by myself) furnish corvée workers. From Yapu they come, from [my] resourceshere, (and) from Nuribta. And may the king, my lord, take cognizance of his city." -EA 365, lines 1-31 (complete)