New Living Translation
Dear brothers and sisters, here’s an example from everyday life. Just as no one can set aside or amend an irrevocable agreement, so it is in this case.

American Standard Version
Brethren, I speak after the manner of men: Though it be but a man's covenant, yet when it hath been confirmed, no one maketh it void, or addeth thereto.

Berean Study Bible
Brothers, let me put this in human terms. Even a human covenant, once it is ratified, cannot be canceled or amended.

Douay-Rheims Bible
Brethren (I speak after the manner of man,) yet a man's testament, if it be confirmed, no man despiseth, nor addeth to it.

English Revised Version
Brethren, I speak after the manner of men: Though it be but a man's covenant, yet when it hath been confirmed, no one maketh it void, or addeth thereto.

King James Bible
Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.

World English Bible
Brothers, speaking of human terms, though it is only a man's covenant, yet when it has been confirmed, no one makes it void, or adds to it.

Young's Literal Translation
Brethren, as a man I say it, even of man a confirmed covenant no one doth make void or doth add to,

Galatians 3:15 Additional Translations ...