Because Israel Have Deserted YHWH And Looked To Others, (Both Nations And Gods), In Spite Of Having Received His Abundant Instruction, He Will Desert Them And They Will Return To Egypt And See Their Cities Destroyed By Fire (Hosea 8:8-14).
The argument now swings to consider Israel's attitude towards other nations. YHWH had delivered Israel from Egypt in order that they might look to Him and to Him alone. But far from doing this Israel were hiring lovers and looking to Assyria. Well, they would soon discover that that was costly. Being under ‘the king of the princes' did not come cheap. And meanwhile they are multiplying altars at which they can sin, in spite of YHWH having provided them with abundant instruction.
In consequence YHWH will take note of their sin and ‘return them to Egypt', that is, bring them once more into slavery and subjection. And this because by their actions they have forgotten their Maker and put their trust in fortified cities which can easily be put to the flame.
Analysis of Hosea 8:8-14.
a Israel is swallowed up. Now are they among the nations, as a vessel in which none delights (Hosea 8:8).
b For they are gone up to Assyria, a wild ass alone by himself, Ephraim has hired lovers (Hosea 8:9).
c Yes, because they hire among the nations, now will I gather them, and they begin to be diminished, by reason of the burden of the king of princes (Hosea 8:10).
d Because Ephraim has multiplied altars for sinning, altars have been to him for sinning (Hosea 8:11).
e I wrote for him the ten thousand things of my law, but they are counted as a strange thing (Hosea 8:12).
d As for the sacrifices of my offerings, they sacrifice flesh and eat it, but YHWH does not accept them (Hosea 8:13 a).
c Now will he remember their iniquity, and visit their sins, they will return to Egypt (Hosea 8:13 b).
b For Israel has forgotten his Maker, and built palaces, and Judah has multiplied fortified cities (Hosea 8:14 a).
a But I will send a fire on his cities, and it will devour its castles. (Hosea 8:14 b).
Note that in ‘a' Israel is swallowed up, and rejected, and in the parallel its cities and castles are devoured by fire. In ‘b' Israel has gone up to Assyria for protection, and has hired lovers, and in the parallel he has looked to fortified cities for protection, and has forgotten his Maker. In ‘c' Israel begin to be diminished as a result of the burden of the king of Assyria, and in the parallel their iniquities are remembered and their sins are visited on them in that they return to Egypt. In ‘d' Ephraim has multiplied altars for sinning, and in the parallel they sacrifice flesh and eat it. Centrally in ‘e' He has written for him ten thousand things of His Law, but they count them as a strange thing.