Charles Ellicott Commentary Hosea 8:9

"For they are gone up to Assyria, [like] a wild ass alone by himself: Ephraim hath hired lovers." — Hosea 8:9 (ASV)

Gone up to Assyria. The word so translated is also used elsewhere for “going up” to the sanctuary of the Lord. (See Note on Hosea 7:11.)

Wild ass is the image of untamed waywardness (Job 39:5 and following). It is described by Wetzstein as inhabiting the steppes, a creature of dirty yellow color, with long ears and no horns, and a head resembling a gazelle's. Its pace is so swift that no hunter can overtake it. It is seldom seen alone, but in herds of several hundreds.

From Jeremiah 2:24 we infer that the animal wanders alone after the object of its lust. Israel, like a solitary wild ass, seeks strange loves, courts strange alliances. On the last clause, see Ezekiel 16:32-34. Ephraim pays abnormally for her own shame.