Sentence:  when about 1350 B.C. a treaty was concluded between the king of Mittanni<!--sic--> [...] and the Hittite ruler [...], the former calls upon the gods <WSD>Mitra</WSD>, Indra, Varuna, and the Nâsatya as guarantors of his sworn obligations. 
Meaning of the word marked with <WSD> tags:  A deity invoked in the Hurrian Mitanni of "ca." 1400 BC.