In S07E06 Jon Snow wants to give his sword Longclaw to Jorah Mormont. He does so because Jorah would have been the rightful heir, but Jon knows that Valyrian steel can kill White Walkers.
Jorah rejects the sword anyway, but wouldn't be giving the sword away be shortsighted?
He not only would lose the sword he can kill White Walkers with, but also the sword he knows how to fight with.