Jamieson, Fausset and Brown on Hosea 8:9

9. gone ... to Assyria--referring to Menahem's application for Pul's aid in establishing him on the throne (compare Ho 5:13; 7:11). Menahem's name is read in the inscriptions in the southwest palace of Nimrod, as a tributary to the Assyrian king in his eighth year. The dynasty of Pul, or Phalluka, was supplanted at Nineveh by that of Tiglath-pileser, about 768 (or 760) B.C. Semiramis seems to have been Pul's wife, and to have withdrawn to Babylon in 768; and her son, Nabonassar, succeeding after a period of confusion, originated "the era of Nabonassar," 747 B.C. [G. V. Smith]. Usually foreigners coming to Israel's land were said to "go up"; here it is the reverse, to intimate Israel's sunken state, and Assyria's superiority.

wild ass--a figure of Israel's headstrong perversity in following her own bent (Jr 2:24).

alone by himself--characteristic of Israel in all ages: "lo, the people shall dwell alone" (Nu 23:9; compare Job 39:5-8).

hired lovers--reversing the ordinary way, namely, that lovers should hire her (Eze 16:33, 34).