'Separation' in the Bible

if he doesn't eat at mountain shrines, and doesn't look to the idols that have been erected in Israel's house, if he doesn't defile his neighbor's wife or approach a woman during her time of menstrual separation,

in thee have they discovered their fathers' nakedness; in thee have they humbled her that was unclean in her separation.

Its priests have wronged My law, And they pollute My holy things, Between holy and common they have not made separation, And between the unclean and the clean they have not made known, And from my sabbaths they have hidden their eyes, And I am pierced in their midst.

Son of man, when the house of Israel dwelt in their own land, they defiled it by their way and by their doings: their way was before me as the uncleanness of a woman in her separation.

He measured it by the four sides: it had a wall round about, five hundred reeds long, and five hundred broad, to make a separation between the sanctuary and the profane place.