Disclaimer: Nope, not a bit of it's mine. It's all the sub-creation of Professor Tolkien. All dialogue in this little tale is taken directly from the chapter 'The Land of Shadow' in The Return of the King.

To Water the Dust

They had trudged for more than an hour when they heard a sound that brought them to a halt. Unbelievable, but unmistakable. Water trickling. Out of a gully on the left, so sharp and narrow that it looked as if the black cliff had been cloven by some huge axe, water came dripping down: the last remains, maybe, of some sweet rain gathered from sunlit seas, but ill-fated to fall at last upon the walls of the Black Land and wander fruitless down into the dust.

J.R.R. Tolkien, The Return of the King, 'The Land of Shadow'

The very earth lies under shadow here, dry and accursed. So long has it been thus, that the rocks do not remember the feel of water, and the dust is undisturbed. They lie still and parched, and they have no memory, for there is no life here. But now there is a change. High up in the cliff-wall, there is a little tumult of tiny stones that, pushed aside, skitter down to the lower slopes. There is another sound now, almost like an echo of music, faint and far off, may be a memory of an echo only. And yet, it flows over the ancient dry stones and stirs their slumbering memories with its cool touch. Water. This is water. Only a little trickle, lost and ill-fated perhaps to fall upon the Dead Land, but enough.

The wanderers pause. They are small, and filthy, clad in rags and foul garments. They look very much like the land itself, and perhaps they too have forgotten the feel of water. They pause, as though they cannot quite believe what they hear, then as one they spring towards the sound.

'If ever I see the Lady again, I will tell her!' cries the stronger one. 'Light and now water!' But then he stops, and turns to the other, the burdened one, and he says, 'Let me drink first, Mr. Frodo.'

'All right,' says the other, and in other lands, where the sun shines and the grass is green, he might have been laughing. Here, the sound is cracked and broken. 'But there's room enough for two.'

'I didn't mean that,' says the stronger one. 'I mean: if it's poisonous, or something that will show its badness quick, well, better me than you, master, if you understand me.'

At first the burdened one seems not even to hear him. He is thinking of old and bright tales heard round an Elvish hearth, when the world was still green. He remembers the tales of the Lord of Waters, who is ever faithful and never forsakes Middle-earth, and he smiles. Then he turns to the other, and he says, 'I do. But I think we'll trust our luck together, Sam; or our blessing. Still, be careful now, if it's very cold!'

The wanderers come then side by side and plunge their hands in the little rill. It is cool but not icy, and each drinks his fill. The strong one's hands are large and brown, calloused with much work, and he drinks quickly, as one who is used to taking swift draughts before returning to his labours. But the burdened one's hands are white and fair, though they too are calloused now, and fraught with many small scars; he drinks slowly, and his eyes are closed, as one who is thankful beyond measure, and would weep if he could. The water is bitter, and mixed with the foul oils of the Black Land, but the wanderers do not notice. To them, it tastes of sunlight and spring air and the memory of home.

The stronger one fills the water bottles, and with a last look they turn away and continue on their road for several miles before turning east. Had they turned back then, they might have heard the trickling water slow to a drip. Soon it disappears altogether, seeping down into the dust, and no new waters follow it. At last no moisture remains in the dry ground to mark that any water had been there, and the rocks and the dust cannot recall it.

But the wanderers do not turn back. They struggle onward, their strength and will renewed. And that night, when they cast themselves down on the barren rocks to watch and to sleep in turns, the burdened one dreams of the Sea.

But Ulmo was alone, and he abode not in Valinor, nor ever came thither unless there were need for a great council; he dwelt from the beginning of Arda in the Outer Ocean, and still he dwells there. Thence he governs the flowing of all waters, and the ebbing, the courses of all rivers and the replenishment of springs, the distilling of all dews and rain in every land beneath the sky. In the deep places he gives thought to music great and terrible; and the echo of that music runs through all the veins of the world in sorrow and in joy; for if joyful is the fountain that rises in the sun, its springs are in the wells of sorrow unfathomed at the foundations of the Earth.

J.R.R. Tolkien, The Silmarillion, 'Of the Beginning of Days'