Nehemiah 9:2

9:2 Those truly of Israelite descent separated from all the foreigners, standing and confessing their sins and the iniquities of their ancestors.

Nehemiah 10:28

10:28 “Now the rest of the people – the priests, the Levites, the gatekeepers, the singers, the temple attendants, and all those who have separated themselves from the neighboring peoples because of the law of God, along with their wives, their sons, and their daughters, all of whom are able to understand –

Ezra 10:11

10:11 Now give praise to the Lord God of your fathers, and do his will. Separate yourselves from the local residents and from these foreign wives.”

James 1:27

1:27 Pure and undefiled religion before God the Father is this: to care for orphans and widows in their misfortune and to keep oneself unstained by the world.