Quoting Commentary for II Kings 16:8

ותשרי וגו׳ And thou gavest,¹²A. V., And thou wentest. etc. There is yet another evil, says the Lord, to Israel; thou hast not only worshipped idols, thou hast also sent presents to the kings of Assyria or Egypt, and hast relied on them.¹³Comp. c. xxx. and xxxi.; Hos. 14:4; 2 Kings 16:8, 17:4. As to the meaning of ותשרי and thou gavest a present, comp. ותשורה and a present (1 Sam. 9:7); R. Moses Hannagid¹⁴R. Moses Hannagid is probably identical with R. Moses Hakkohen. Hannagid means the prince, and is a title given to men of distinction. derives תשורה from שור to see, and explains it to signify the fees for the vision and prophecy; according to this explanation ותשרי may be compared with אשורנו I shall see him (Num. 24:17), and explained thou didst go to see him.

to the king of Yarev This refers to Ahaz, who gave a bribe to Tiglath-pileser to assist him against Rezin the king of Aram and Pekah son of Remaliah (II Kings 16:8).