Howdy.
Thanks for the tissues, ethan...
I was thinking that maybe another way of looking at the "Jack, I swear-" line is to imagine Ennis doing exactly what he did during that scene, but here is the twist (no pun intended): what if he did not say it at all? What does the line add that was not there?
Ennis is a man who does not waste words... so we know that when he said those words he was declaring something MASSIVE. We know it was deeply personal and we know that it has to do with Jack. We know that he reversed the shirts (his is now over Jack's). We know that he has a postcard of Brokeback Mountain. We know that the shirts were *nailed* to a *CLOSET* door. Yet here we have a man who does not say much to anybody and he says "Jack, I swear-" to the shirts and the postcard. Why say it just after the announcement of his daughter's wedding?
Ennis could never commit fully to Jack before and somehow he had to say the words.
I can only imagine the outpouring of love as Ennis said it, because Jack was his true love. I can only imagine how agonizing it was for Ennis as he misses his Jack so much that he can hardly stand it.
I think it was a powerful declaration of his love for Jack and he did not have to say any more, because Jack already knew.
Peace,
Frank (aka Jack Nasty)