Marriage is about defining mutual obligations. Not social obligations
Sure...it's good to speak the truth...good to abstain from violence. But these principles do not define the relationship with your spouse. They are applicable to any social interaction
Eg - A common Sanskrit statement that features in Hindu ceremonies is this -
dharme cha, arthe cha kaame cha imam na ati charaami
That is very specific. Not every Tom, Dick and Harry on the street is your sahayogi in this respect.
It is not generic. Not about parroting vague ethical principles
It's about becoming cognizant of mutual responsibilities to one another for the rest of life's journey