Parallel
Mark 10:8
Patriarchal Greek New Testament (1904) · Berean Standard Bible
ὥστε οὐκέτι εἰσὶ δύο, ἀλλὰ μία σάρξ·
and the two will become one flesh (note: Genesis 2:24 (see also LXX)).’ So they are no longer two, but one flesh.