As part of this new larger role, Rey and Maz are actually traveling together early in the film, which includes a scene where Maz explains how she came by the lightsaber she gave to Rey in Star Wars: The Force Awakens.
As with all rumors, grains of salt should be liberally applied, but according to this unconfirmed report, Maz Kanata will have a much larger role in Star Wars Episode IX than her cameo appearance in The Last Jedi.
He then turned the lightsaber over to Maz, believing she would know what to do with it.
Apparently, Lando Calrissian returned to Cloud City at some point after Return of the Jedi and came across the weapon, apparently literally sitting in a lost and found box that had been collected by some of the city’s Ugnaught inhabitants.