Psalm 8.2
Septuagint



ek stomatoV nhpiwn kai 
qhlazontwn kathrtisw ainon: 
eneka twn ecqrwn sou, tou katalusai  ecqron kai ekdikhthn

New Testament - Matthew 21.16

kai eipan autw:  akoueiV ti outoi legousin; o de IhsouV legei autoiV:  nai.  oudepote anegnwte oti 
ek stomatoV nhpiwn kai 
qhlazontwn kathrtisw ainon
 

Septuagint

Out of the mouths of babes and sucklings has thou perfected praise, because of thine enemies; that thou mightest put down the enemy and avenger

New Testament

and said unto him, Hearest thou what these are saying?  And Jesus saith unto them, Yea:  did ye never read, Out of the mouth of babes and sucklings thou hast perfected praise?

Masoretic Text

Out of the mouths of babes and sucklings hast thou established strength, because of thine adversaries, that thou mightest still the enemy and avenger

Comments:  The MT has “established strength” in place of “perfected praise.”