This portion discusses the purification of the metzorah, or leper, and ends with the laws pertaining to one who experiences an impure bodily discharge.
The Portion of Metzorah

וַיְדַבֵּר יְהֹוָה אֶל־מֹשֶׁה לֵּאמֹר׃ Hashem spoke to Moshe, saying: וְהַדָּוָה בְּנִדָּתָהּ וְהַזָּב אֶת־זוֹבוֹ לַזָּכָר וְלַנְּקֵבָה וּלְאִישׁ אֲשֶׁר יִשְׁכַּב עִם־טְמֵאָה׃ and concerning her who is in menstrual infirmity, and concerning anyone, male or female, who has a discharge, and concerning a man who lies with an unclean woman.