The Bible’s prophets use marriage to discuss relations between gods and nations. Yahweh was ‘married’ to Israel, for example.
Jesus- the ‘Bridegroom’- speaks as a prophet to that higher narrative of deities married to ‘nations’ and the problem of Israel, Yahweh’s ex-wife.
Note: reading Mt 19 to refer to Christian marriage would make getting a divorce a capital crime. Adultery = death! To invoke Mt 19 against divorced people is to call for them to be executed.