semiopen

I didn't understand this either until I looked at the story and some commentary after your first post.

The marriage is not specifically stated in the text but Delilah is referred to as "isha" (woman/wife) as opposed to "isha zona" (harlot) from the previous verse. If she were not married then "isha zona" would be used.

This is convincing to me, and apparently to the commentators. It would be interesting to hear the preacher's side but I suspect his interpretation shows a gap in his education.