'Unclean' in the Bible

Then Haggai said, Will any of these be made unclean by the touch of one who is unclean through touching a dead body? And the priests answering said, It will be made unclean.

Then Haggai said, So is this people and so is this nation before me, says the Lord; and so is every work of their hands; and the offering they give there is unclean.