Exodus 21.17
Septuagint

o kakologwn patera autou h mhtera autou, teleuthsei qanatw

New Testament - Matthew 15.4

o gar qeoV eipen:  tima ton patera kai thn mhtera, kai , 
o kakologwn patera h mhtera qanatw teleutatw

Mark 7.10

MwushV gar eipen:  tima ton patera sou kai thn mhtera sou, kai,
o kakologwn patera h mhtera qanatw teleutatw

Septuagint

He that reviles his father or his mother shall surely die

New Testament

Matthew 15.4:  For God said, Honor thy father and thy mother:  and, He that speaketh evil of father or mother, let him die the death

Mark 7.10:  For Moses said, Honor thy father and thy mother; and, He that speaketh evil of father or mother, let him die the death

Masoretic Text

And he that curseth his father or his mother, shall be surely put to death

Comments:  The NT, LXX and MT agree.  This is Exodus 21.16 in the Septuagint. 

The slight difference in the LXX and NT Greek - “shall surely die” versus “let him die” - is removed in Codex Alexandrinus.