'Impurity' in the Bible

"'If a woman has a discharge, and her discharge in her flesh is blood, she shall be in her impurity seven days: and whoever touches her shall be unclean until the evening.

"'Everything that she lies on in her impurity shall be unclean. Everything also that she sits on shall be unclean.

"'If a man takes his brother's wife, it is an impurity: he has uncovered his brother's nakedness; they shall be childless.