Isaiah 59:20-21

20“A Redeemer (Messiah) will come to Zion, And to those in Jacob (Israel) who turn from transgression (sin),” declares the Lord.

21“As for Me, this is My covenant with them,” says the Lord: “My Spirit which is upon you [writing the law of God on the heart], and My words which I have put in your mouth shall not depart from your mouth, nor from the mouths of your [true, spiritual] children, nor from the mouth of your children’s children,” says the Lord, “from now and forever.”