'Separate' in the Bible

And I separate from the heads of the priests, twelve, even Sherebiah, Hashabiah, and with them of their brethren ten,

Now after these things were done, the captains came to me and said, The people of Israel and the priests and Levites have not kept themselves separate from the people of the lands, but have taken part in the disgusting ways of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites.

Now therefore make confession unto the LORD God of your fathers, and do his pleasure: and separate yourselves from the people of the land, and from the strange wives.