Those truly of Israelite descent ¹  separated from all the foreigners, ²  standing and confessing their sins and the iniquities of their ancestors. ³ 

These are the ones who came up from Tel Melah, Tel Harsha, Kerub, Addon, and Immer (although they were unable to certify ¹  their family connection ²  or their ancestry, ³  as to whether they were really from Israel):

When you perceived that his heart was faithful toward you, you established a ¹  covenant with him to give his descendants ²  the land of the Canaanites, the Hittites, the Amorites, the Perizzites, the Jebusites, and the Girgashites. You have fulfilled your promise, ³  for you are righteous.