Hosea 9:4

‘They will not pour out wine-offerings to YHWH,

Nor will they be pleasing to him,

Their sacrifices will be to them as the bread of mourners,

All who eat of it will be polluted,

For their bread will be for their appetite,

It will not come into the house of YHWH.'

And once in exile there will be no more wine offerings to YHWH, or any other offering. The wine offering was poured out beside the altar when sacrificing, and here stands for all the non-bloody offerings. But there would be no more wine-offerings because there would be no more sacrifices. Furthermore nothing that they did would be pleasing to Him. And if they were to offer sacrifices (to foreign gods), such sacrifices would be unclean like bread which was eaten by mourners. Food eaten by mourners was necessarily unclean because of its contact with the dead. Thus to participate in anything like that would make them polluted.

Alternately it may signify that the very thought of sacrifices offered to YHWH would remind them of how they had dishonoured Him and debased His sacrifices. Indeed all their meat eaten in foreign lands would be ‘unclean' because it had not been offered to YHWH. The provisions for sanctifying meat and offering it to YHWH (Deuteronomy 12:20) would not apply in a foreign land. Thus whatever they ate would be unclean and would merely be in order to satisfy their appetites. It would not be food offered to YHWH. It would not have come into ‘the house of YHWH'. This may signify the land of Israel seen as YHWH's dwellingplace, or to the Temple in Jerusalem. Even in Israel it was possible for them to pour out the blood as described in Deuteronomy 12 as though it had been done in the Temple, for the whole land was YHWH's. But it would not be true in Assyria.

We might not be too appalled at the thought, but even to faithless Israel the thought of eating food not offered to YHWH in one way or another would have been abhorrent.