Jeremiah 9.24
Septuagint

all h en toutw kaucasqw o kaucwmenoV
suniein kai ginwskein, 
oti egw eimi kurioV
 

New Testament - 1 Corinthians 1.31

o kaucwmenoV en kuriw kaucasqw 

2 Corinthians 10.17

o de kaucwmenoV en kuriw kaucasqw

Septuagint

but let him that boasts boast in this, the understanding and knowing that I am the Lord

New Testament

1 Corinthians 1.31: He that glorieth, let him glory in the Lord

2 Corinthians 10.17:  But he that glorieth, let him glory in the Lord

Masoretic Text

but let him that glorieth glory in this, that he hath understanding, and knoweth me, that I am Jehovah

Comments:  The NT, LXX and the MT agree.  The quotation is loose.