Genesis 22.18
Septuagint

kai eneuloghqhsontai 
en tw spermati sou
panta ta eqnh thV ghV
anq wn uphkousaV thV emhV fwnhV

New Testament - Acts 3.25

umeiV este oi uioi twn profhtwn kai thV diaqhkhV hV dieqeto o qeoV proV touV pateraV umwn legwn proV Abraam:  
kai en tw spermati sou 
eneuloghqhsontai 
pasai ai patriai thV ghV

Septuagint

And in thy seed shall all the nations of the earth be blessed, because thou hast hearkened to my voice 

New Testament

Ye are the sons of the prophets, and of the covenant which God made with your fathers, saying unto Abraham, And in thy seed shall all the families of the earth be blessed

Masoretic Text

and in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice

Comments:  The NT, LXX and MT agree.