It has not left his side for 28 years… Neither has his cane…. *goes back to an old theory of mine*, at which everyone laughed, and it does not quite add up, because he did use the dagger to summon the wraith… on the other hand, a kris still is a magical object, whether it is THE dagger, or A dagger.
Or maybe he split the dagger somehow.
I can’t believe he would just tell them, when he is coming back to Storybrooke within 24 hours or literally will die trying. He’s not that stupid.