GOD'S WORD® Translation
"This is my promise to them," says the LORD. "My Spirit, who is on you, and my words that I put in your mouth will not leave you. They will be with your children and your grandchildren permanently," says the LORD.

American Standard Version
And as for me, this is my covenant with them, saith Jehovah: my Spirit that is upon thee, and my words which I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy seed, nor out of the mouth of thy seed's seed, saith Jehovah, from henceforth and for ever.

Berean Study Bible
“As for Me, this is My covenant with them,” says the LORD. “My Spirit will not depart from you, and My words that I have put in your mouth will not depart from your mouth or from the mouths of your children and grandchildren, from now on and forevermore,” says the LORD.

Douay-Rheims Bible
This is my covenant with them, saith the Lord: My spirit that is in thee, and my words that I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy seed, nor out of the mouth of thy seed's seed, saith the Lord, from henceforth and for ever.

English Revised Version
And as for me, this is my covenant with them, saith the LORD: my spirit that is upon thee, and my words which I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy seed, nor out of the mouth of thy seed's seed, saith the LORD, from henceforth and for ever.

King James Bible
As for me, this is my covenant with them, saith the LORD; My spirit that is upon thee, and my words which I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy seed, nor out of the mouth of thy seed's seed, saith the LORD, from henceforth and for ever.

World English Bible
"As for me, this is my covenant with them," says Yahweh. "My Spirit who is on you, and my words which I have put in your mouth, shall not depart out of your mouth, nor out of the mouth of your seed, nor out of the mouth of your seed's seed," says Yahweh, "from henceforth and forever."

Young's Literal Translation
And I -- this is My covenant with them, said Jehovah, My Spirit that is on thee, And My words that I have put in thy mouth, Depart not from thy mouth, And from the mouth of thy seed, And from the mouth of thy seed's seed, said Jehovah, From henceforth unto the age!

Isaiah 59:21 Additional Translations ...