There’s a difference between “some indency” and “unless the marriage is unlawful.”
Check the Hebrew for what that implies. They are equivalent.
Yeah, in the text.
“
Do not think that I have come to abolish the Law or the Prophets;
I did not come to abolish but to fulfill. For truly I say to you, until heaven and earth pass away, not the smallest letter or stroke shall pass from the Law until all is accomplished…Again you have heard that the ancients were told, “
You shall not make false vows, but shall fulfill your vows to the Lord (referring to Leviticus 19:12, Numbers 30:2, Deuteronomy 30:2, Deuteronomy 23:21, Deuteronomy 23:23).” But I say to you, make no oath at all, either by heaven, for it is the footstool of his feet, or by Jerusalem, for it is the city of the Great King. Nor shall you make an oath by your head, for you cannot make one hair white or black. (Notice how Christ provides examples of formulas that Pharisees were allowing the people to use and not be held accountable for their oaths). But let your statement be, “Yes, yes,” or “No, No;” anything beyond these is of evil.”
Again the text here from the beginning shows that Christ is addressing the fact that people are teaching that it is okay to break one’s word so long as you don’t invoke God’s name. Jesus slams the door on this referring back to the original commandments which say you shall not make false vows. Numerous commentaries would support me on this interpretation to include Ellicott’s Commentary, Benson Commentary, Barnes’ Notes, Matthew Poole’s Commentary, Gill’s Exposition, Meyers NT Commentary, The Expositor’s Greek Testament, Bengel’s Gnomen, and the Pulpit Commentary, among others.
Sorry, just realized that was for the wrong part of the passages being discussed, but it stands.