'Deal' in the Bible

Have we not all one father? Hath not one God created us? Why do we deal unfaithfully every man against his brother, by profaning the covenant of our fathers?

And did not one make them? and the remnant of the Spirit was his. And wherefore the one? He sought a seed of God. Take heed then to your spirit, and let none deal unfaithfully against the wife of his youth,

(for I hate putting away, saith Jehovah the God of Israel;) and he covereth with violence his garment, saith Jehovah of hosts: take heed then to your spirit, that ye deal not unfaithfully.