Cross reference
Ezekiel 4:13
13 And the Lord said, Even so the children of Israel will have unclean bread for their food among the nations where I am driving them.
Daniel 1:8
8 And Daniel had come to the decision that he would not make himself unclean with the king's food or wine; so he made a request to the captain of the unsexed servants that he might not make himself unclean.
Hosea 9:3-4
3 They will have no resting-place in the Lord's land, but Ephraim will go back to Egypt, and they will take unclean food in Assyria.
4 They will give no wine offering to the Lord, they will not make offerings ready for him; their bread will be like the bread of those in sorrow; all who take it will be unclean, because their bread will be only for their desire, it will not come into the house of the Lord.