Tolkien devotes an entire chapter to the farewell to Lorien, and in this chapter I have always felt that it is here where he, in effect, transfers the keys of Middle-earth from the Elves to the other races. Advice is given. Food is shared. But it is Galadriel's giving of gifts to the Fellowship that seems to best signify this passage.
It is Galadriel's gift to Sam of the blessed earth from her garden. She does not give him weapons for battle, but life-giving earth so that the abundance of growing things is bequeathed to Sam.
To Frodo she gives the gift of light so that darkness will not dominate Middle-earth, even in its darkest hours.
"May it be a light to you in dark places when all other lights go out."
To Gimli she gives the gift of hope in the guise of three strands of her golden hair, and she reminds him that the real treasure of Middle-earth is not valued in material wealth. As she places the strands in Gimli's hand, she prophecies,
"...on the one hand lies darkness, and on the other only hope. But if hope should not fail, then I say to you, Gimli son of Glóin, that your hands shall flow with gold, and yet over you gold shall have no dominion."
And it is to Aragorn, as is only fitting, that Galadriel bestows the gifts of most significance for the future of Middle-earth. She gives him a sheath for Andúril with the charge,
"The blade that is drawn from this sheath shall not be stained or broken even in defeat." And then she almost speaks a personal farewell to him and Middle-earth,
"For darkness will flow between us, and it may be that we shall not meet again, unless it be far hence upon a road that has no returning." But Tolkien and Galadriel do not leave Aragorn (or us) without hope for the future.
"This stone I gave to Celebrían my daughter, and she to hers, and now it comes to you as a token of hope. In this hour take the name that was foretold for you, Elessar, the Elfstone of the house of Elendil!"