Passage
on this account shall a man leave his father and mother, and shall cleave unto his wife,
on this account shall a man leave his father and mother, and shall cleave unto his wife,
Mark 10:5 And Jesus answering said to them, `For the stiffness of your heart he wrote you this command,
Mark 10:6 but from the beginning of the creation, a male and a female God did make them;
Mark 10:7 on this account shall a man leave his father and mother, and shall cleave unto his wife,
Mark 10:8 and they shall be--the two--for one flesh; so that they are no more two, but one flesh;
Mark 10:9 what therefore God did join together, let not man put asunder.'
The verse centers on "account", "shall", "leave", "father", "mother", "cleave", and "wife". It is saying that the verse draws attention to "account" and "shall", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 6's "but from the beginning of the creation..." into verse 8's "and they shall be--the two--for one flesh...", so "account" and "shall" belong inside that flow. In Mark context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "account" and "shall" with trust shaped by these words, not by a vague optimism outside the passage.